Section Five: Bodyweight

Humans are not designed to sit behind desks all day. We evolved as hunter-gathers who had to hunt animals and fish and forage for wild nuts, seeds and vegetables. Not only were those foods very healthy we had to expend a large amount of physical effort to obtain them. This helped to keep our ancestors lean. We talked about the issues with modern Western diets in the Section Two: Nutrition and the lack of physical activity required by the modern world is another factor that contributes to an increasingly overweight population.

It is well documented that being overweight can lead to a number of health issues including high blood pressure, cancer, diabetes, mental illness and, indeed, death from any cause[1] [2]. In fact, studies conclude that obesity is worse for our health than both smoking and alcohol[3] [4].

Excessive bodyweight is a growing issue in the Western world. Studies have estimated that 56% of women in England[5] and 61% of women in the US[6] are obese, not just overweight.

What can it affect?

               

How can it harm us?

The question, then, is does our bodyweight impact our chances of having a baby? To answer this we first need to understand how bodyweight is categorised.

Most research uses a measurement called the Body Mass Index, or BMI for short. BMI is calculated using our height and weight to produce a number. This number can then be used to determine whether you are underweight or overweight. There are many BMI calculators online and you should use one of these to determine your BMI. We used this one: www.calculator.net/bmi-calculator.html.

Different countries have different classifications of weight but the World Health Organisation categorises BMI as follows:

Category

BMI

 

Underweight

 

Less than 18.5

Normal weight

 

18.5-24.9

Overweight

 

25-29.9

Obesity Class 1

 

30-34.9

Obesity Class 2

 

35-39.9

Obesity Class 3

 

More than 40

Effect of being overweight

A lot of research has been done into the impact of being overweight on fertility and pregnancy. This research demonstrates that obesity in women:

  1. is associated with worse pregnancy outcomes generally, including lower fertility and increased chances of miscarriage[7]
  2. increases the risk of problems during pregnancy such as pre-eclampsia, diabetes and still births[8]
  3. is linked to increased risk of birth defects and growth abnormalities in children[9]
  4. causes the same risks in IVF patients as it does in natural pregnancies[10] [11]

Men who are overweight also experience issues. For example:

  1. a Danish study[12] of 47,835 couples found that where men had a BMI of greater than 30 the couples had a 53% increased risk of taking more than 12 months to get pregnant. Where the female partner was also obese the risk increased by 175%
  2. in a Norwegian study[13] of 26,303 pregnancies the chances of not conceiving within 12 months increased by 20% for overweight men and 36% for obese men. This study looked at pregnancies so obviously did not include couples that failed to conceive. The consequence of this is that these percentages are likely to be conservative
  3. a US study[14] found that for every 3 point increase in BMI the risk of poor fertility increased by 21%

The reason that the male partner’s bodyweight is an issue appears to be due to excess weight causing a combination of lower sperm count[15] and poorer sperm quality[16].

When we look specifically at how bodyweight affects IVF success the following picture emerges:

  1. overweight and obese women require higher doses of stimulating drugs to trigger ovulation and these drugs are less effective[17]
  2. egg retrieval is more difficult in obese women[18]
  3. overweight women have significantly fewer eggs retrieved than normal weight women[19]
  4. egg fertilisation rates are lower in obese women[20]
  5. obese women have fewer high-grade embryos[21]
  6. overweight women are 83% more likely to have a cycle cancelled due to poor response than normal weight women[22]
  7. poor response rates amongst obese women are 28.2% compared to 16.9% in normal weight women[23]
  8. normal weight women have embryo implantation rates of 24% compared to just 15% for overweight women[24]
  9. normal weight women have a 40% higher chance of achieving pregnancy than overweight and obese women[25]
  10. the chances of miscarriage are 33% higher in overweight women and 53% higher in obese women[26]

The above studies lead us to the key measurement which is, of course, live birth rates. A study[27] of 4,609 women undergoing IVF treatment with multiple embryo transfers between 2004 and 2010 showed decreasing chances of live birth with increasing weight. The researchers divided the women into four groups: normal weight, overweight, obese and morbidly obese. The results were as follows:

Group

Chance of Live Birth

 

Reduction in Chance of Live Birth

 

Normal

 

96%

N/A

Overweight

 

63%

 

33% lower than normal weight group

 

Obese

 

39%

 

57% lower than normal weight group

 

Morbidly Obese

 

32%

 

64% lower than normal weight group

 

Where the male partner is overweight studies also show that pregnancy rates drop significantly. There is less research in this area however in one study[28] pregnancy rates dropped from 46.7% in couples with normal weight male partners to 32% for couples with overweight male partners. Another study[29] showed a similar impact with couples where the male partner was overweight having a pregnancy rate of 33.6% compared to 53.2% in couples with a normal weight male partner.

Effect of being underweight

Less research has been done on IVF success of underweight women. This is a little surprising as it has been shown that being underweight can be as problematic for fertility generally as being overweight[30]. From the available studies it seems clear that being underweight impacts the chances of IVF success too. For example, one study[31] examined the outcome of 2,362 IVF cycles using multiple embryos, dividing women into three groups: underweight, normal weight and obese. The researchers found that the normal weight group had a 50% chance of a live birth whereas the underweight group had only a 34% chance of a live birth.

A study[32] of 1,107 Chinese women undergoing IVF found that underweight women were 16% less likely to become pregnant compared to normal weight women.

I could not find any study assessing the impact of underweight men undergoing IVF however there are a few studies on the fertility of underweight men generally and these are worth mentioning. For example, a study[33] of 1,558 Danish men found that those with a BMI of less than 20 had a reduction in sperm concentration of 28.1% and a reduction in sperm count of 36.4%.

Another study[34] involving 2,037 men found that those with a BMI of less than 20 had a 68% increased risk of low semen volume and a 56% increased risk of having abnormal sperm.

The ideal BMI

So, it seems clear that for both women and men being either overweight or underweight can negatively affect chances of IVF success. On top of this the more overweight or underweight someone is the greater the impact.

Looking at the research a BMI of between 20 and 25 seems to be optimal. The UK National Institute for Health and Care Excellence recommends a BMI for women of 19 to 30[35] but the studies suggest that chances can be improved by narrowing the range.

If you are not currently within this range there is some positive news. It has been shown[36] that in women whose infertility is due to being underweight correcting the issue led to 70% of the women studied conceiving without the need for assisted techniques. For women that are overweight, losing weight led to fertility being restored[37] and another study showed that IVF patients that lost weight experienced better egg retrieval[38].

What can we do?

If you are not currently within the ideal BMI range what can you do to address the issue? We’ll first look at what you can do if you’re overweight then look at what you can do if you’re underweight.

Overweight

If you are overweight there is a lot you can do and, unless you have a medical condition that impacts your bodyweight, losing “weight” is completely within your control. Before we get into the detail of the things you can do it is important to first clarify something. Whilst people often talk about losing “weight” they should really be talking about losing fat. This distinction is important as we do not want to lose lean tissue. Unfortunately, this is exactly what many fad and commercial diets result in.

The usual advice to lose weight is “eat less, exercise more” but science can provide a better and more structured approach. Diet and exercise are important but there are a number of other things we can do to increase the likelihood of success. Let’s have a look at them now.

Diet: another diet mantra is “calories in, calories out”. This is based on the belief that all calories are created equal (is 100 calories of doughnut really the same as 100 calories of lettuce?!) and that to lose weight you must burn more calories than you consume. It is beyond the scope of this Plan to dissect the faulty premises underpinning these mantras but I will just say that whilst burning more calories than we consume is a factor there is much more to it. The quality and type of food we consume are key.

Whether you follow the advice set out below is, of course, your choice. If you chose not to do so and instead opt for another approach please be very careful. Diets that severely restrict calories can exacerbate bodyweight issues in the medium/long term and disrupt the delicate hormonal balance critical to fertility.

By cutting calories people often see quick results on the scales but the result is that our bodies think we are in starvation mode (remember we have not evolved much from times when food could be scarce) and so takes action to slow down the rate at which we burn calories. This is an effort to help us survive for as long as possible.

The initial drop in weight is usually just water and carbohydrate stored in our muscles which returns when normal eating is resumed. Our body also keeps the amount of calories we burn low so that we put back on weight as a protection mechanism just in case we encounter another “starvation” period.

What makes things worse is that it does not just wait until we have returned to previous weight levels it waits until we have added a bit more fat as “insurance” in case we have another “starvation period”. This worked well when we were hunter-gatherers but just leads to yo-yo dieting in modern times.

To lose fat and keep fat off we need to do things differently. We need a diet approach that provides all the nutrition we need and does not trigger our body’s starvation response. You may not realise it but (if you have read this Plan in order!) you already know of such an approach… the MDWT.

One of the key benefits of a Mediterranean diet is that it helps us become healthier and part of becoming healthier is stabilising bodyweight. Without taking any other measures studies[39] show that the Mediterranean diet leads to fat loss over the long term and is more effective than low-fat diets. Fat loss has also been shown over the long term where study participants’ calorie intake was not restricted[40]. People ate as much as they wanted and still lost weight.

I mentioned above that the traditional Mediterranean diet is not perfect and the tweaks set out in Section Two: Nutrition are helpful not just from an IVF success perspective, they are also helpful from a fat loss perspective.

So, to lose fat and keep it off follow the MDWT.

Breakfast: it is often said that breakfast is the most important meal of the day. I agree. It is also when many people consume foods that set themselves up badly for the day. In Western diets people typically eat some form of cereal, baked goods or other carbohydrate-heavy breakfast. The issue with this is that, for many people, these foods screw up their blood sugar levels for the day which results in them eating more and eating more of the “wrong” type of foods later on.

Carbohydrates (particularly the highly refined variety found in typical Western breakfasts) cause a sharp rise in blood sugar levels in our bodies which is shortly followed by a crash. When blood sugar levels drop we get hungry, tired, irritable and crave carbohydrates and sugar-laden foods. This is not the case for everyone, some people tolerate carbohydrates well. If you are one of those people then count yourself lucky.

To test your tolerance to carbohydrates try this experiment: for a week consume 1-2 pieces of white toast with jam or honey at your normal breakfast time and note the time that you start to feel hungry again. Also note down whether you feel tired or energised, calm or irritable. For the next week replace the toast with a breakfast of meat and nuts at the same time as you ate the toast. That’s right, meat and nuts! About 80-100 grams of lean meat of your choice and a handful of raw nuts with the skin on is about right. Again, note down the time you begin to feel hungry and whether you feel tired or energised, calm or irritable. If your body does not tolerate carbohydrates well it is likely that you will see a marked difference in the results. You should feel fuller for longer, more energised and calmer with the meat and nuts breakfast. You should also find that you do not crave carbohydrate-heavy foods as much.

Why does it work? The protein in the meat and nuts causes a slow rise in blood sugar levels which in turn avoids the crash. The healthy fats in the nuts help with the production of chemicals called neurotransmitters which keep our minds sharp and also raise blood sugar levels slowly.

Studies have shown that the addition of protein to meals leads to reduced appetite and increased feelings of fullness[41] [42] [43]. In addition, when protein is eaten at breakfast it results in greater feelings of fullness than if the same amount of protein is consumed at lunch or dinner[44]. In fact, a study[45] showed that participants who ate protein for breakfast in the form of eggs ate up to 300 calories less at lunch and dinner than participants who ate either cornflakes with milk, toast and orange juice or a croissant and orange juice. Over time this reduction will result in significant fat loss.

The meat and nuts breakfast is probably one of the more “out there” tips contained in this Plan. I cannot take credit for it. It was brought to people’s attention by a Canadian Olympic coach called Charles Poliquin. My wife and I both tried it as part of her weight loss efforts and we are still eating it four years later. The increased energy and leanness it has given us is significant.

Of course, some people are allergic to nuts so have to avoid them. If you are one of these people then you can substitute nuts for certain fruits that have been shown to cause slow rises in blood sugar levels. Not all fruits do this so stick to the following: berries, apricots, peaches, nectarines, plums and grapefruit. Even if you are not allergic to nuts be sure to rotate the type every few days to prevent food intolerances developing.

Eat more protein: in Section Two: Nutrition we saw the benefits of eating sufficient protein on IVF success. Consuming more protein also has a major positive impact on fat loss. A whole book could be written on these benefits but I will summarise the major ones here. Eating protein:

  1. increases the levels of hormones that make us feel full and reduces the levels of hormones that make us feel hungry[46] [47]
  2. results in 20-30% of the calories consumed being burned as part of the digestion process compared to 5-10% of calories from carbohydrate and 0-3% from fat[48]. So, if we eat 500 calories of protein only 350-400 calories end up being used by the body
  3. causes our bodies to burn more calories generally. Studies have shown increases of up to 100 calories per day[49] [50]
  4. at 30% of daily calories reduces appetite by as much 441 calories a day[51]
  5. reduces cravings by 60%[52]
  6. causes fat loss without reducing calories[53] [54]
  7. is correlated with less belly fat, a particular type of fat linked to a variety of illnesses[55]

How much protein should you consume? Tweak 4 of Section Two: Nutrition gives us the answer. The same amount of protein per day both improves our chances of success with IVF and gives us the fat loss benefits described here. Aim to get between 25% and 35% of your calories from good quality protein each day.

Motivation: if you choose to lose fat to attain an ideal BMI as part of preparation for IVF then your reasons for doing so, and therefore your motivations, should already be clear: an ideal BMI will help maximise your chances of having a child. This will most likely be the most powerful motivating force available to you and the goal setting principles contained in Section One: Our Minds also apply here. You can use them to create a sub-goal of achieving an ideal BMI as part of the overall goal of having a child.

Having said that, in the spirit of taking every step possible to increase our chances of success it is worth utilising other sources of motivation to further boost our prospects. When it comes to fat loss there is a specific step we can use to increase our motivation and therefore our chances of reaching an ideal BMI.

That step is taking photographs of ourselves from the front, back and sides at the start of the fat loss phase and then taking further photographs each week until you have achieved your aim. I’ll be honest, you will probably not like the “before” photographs and they may look worse than you expect (they usually do) but doing this has been shown to be a powerful tool to increase adherence to fat loss plans[56].

Chewing food properly: portion control, or more precisely a lack of it, is regarded as one of the major reasons why people become overweight. Eating even a little too much at each meal over weeks, months and years gradually builds up and piles on the pounds. When you consider that the size of restaurant portions has increased over the years, the size of food packages has grown and average plate size has also increased it is easy to see how we can overeat. Given the significance of the issue to weight management it is important to look at measures to address the issue. Fortunately, there are a number of simple things we can do.

What follows may be one of the easiest things we can do to lose body fat. It is so simple and so well researched that it is surprising that we don’t hear more about it.

Simply chewing food properly leads to the consumption of fewer calories which in turn helps us lose fat.

If you are like most people you do not chew your food properly, especially when you are in a hurry. Chewing is the first stage of the digestion process and the way we chew and how long we chew can have a significant impact on our overall health, including our body fat levels.

An example of the impact of chewing slowly can be found in a 2014 study[57] which took a group of 70 men and women and had them eat at a slower speed, chewing their food properly. The researchers found that the participants consumed between 57 and 88 fewer calories per meal than participants that ate at their normal speed. 57-88 calories may not sound a lot but over time it amounts to a substantial difference which, again, will result in significant fat loss.

Another study[58] took a group of participants, measured the number of times they typically chewed their food and then looked at the effects of increasing the number of chews by 50% and 100%. By increasing the number of chews by 50% participants consumed 9.5% less food and by doubling the number of chews their food intake decreased by 14.8%.

It is not just a reduction in the amount of food we eat that chewing properly causes, it has also been shown to:

  1. increase the feeling of fullness [59]
  2. help prevent diabetes[60]
  3. reduce the desire to snack between meals[61]
  4. increase our ability to absorb nutrients from food[62]
  5. increase appetite-regulating hormones that tell us to stop eating[63]

In addition to chewing food properly, speed of eating is important. A study[64] of 30 women looked at the effect of eating quickly until comfortably full and slowly (by putting down cutlery in between mouthfuls) until comfortably full. When eating quickly the group ate on average 646 calories but when eating slowly the group ate 579 calories, 67 calories less. The group also reported being more hungry one hour after the quick eating session.

Chewing food quickly and eating until full has been shown[65] to triple the risk of becoming overweight.

Why does chewing more slowly work? One reason relates to our bodies’ signalling mechanism which tells us when we are full. It takes some time for this signalling mechanism to work and when we eat quickly we may have already overeaten by the time the signalling process has kicked in. Result: we have already consumed more calories than we need by the time our body tells us we are full!

So how many times should we chew each mouthful to get these benefits? There are a number of studies that have looked at this but trying to specify a precise number is difficult and would make mealtimes a chore. Add in the fact that different foods have different consistencies, some taking longer to chew than others, and there has to be a better way.

There is. Simply chew each mouthful until it is liquefied before swallowing.

This will take some conscious thought to start with but will soon become a habit. You can make the transition easier by following a few simple rules:

  1. set aside time to eat, don’t eat in a hurry
  2. eat in a calm environment
  3. be mindful when eating. Put away your phone, tablet, laptop, etc and turn off the TV!
  4. take smaller bites
  5. put your cutlery down between each mouthful
  6. chew until the food is a puree and finish one mouthful completely before moving on to the next

Drinking water before meals: another simple and apparently little-known (at least according to a poll of my friends and colleagues) portion control tip is to drink water. This has been shown to be beneficial to fat loss efforts in two ways: by burning more calories and reducing appetite. In itself drinking water is unlikely to lead to large fat loss but it is an easy thing to do to increase the effectiveness of your efforts.

It may surprise you to learn that just drinking water leads to an increase in the number of calories we burn. Plain water, of course, is calorie-free but our bodies still have to work to digest and use it. In one study[66] drinking 500ml of water was shown to increase calories burnt by 30% following consumption. This equates to around 24 calories. In itself it is not much but it is easy to see how this can add up over time. Another study[67] showed that the increased calorie burning continued for 60 minutes following consumption.

When it comes to appetite reduction the effects of drinking water appear to be more pronounced. For example, a study[68] gave participants 500ml of water 30 minutes prior to a meal then examined the energy intake (amount of calories) consumed. On average those who drank the water consumed 13% fewer calories. This equated to an average reduction of 74 calories for a single meal.

Another study[69] looked specifically at the fat loss effects of increased water consumption. All participants were put on the same fat loss diet with half also drinking 500ml of water within 30 minutes prior to eating and the other half did not consume anything. Over the course of the 12 week study period the group drinking water lost 2kg more weight than the non-water group. For such a simple step that is a sizable difference.

A study[70] of 50 overweight women had the participants consume 500ml of water before each meal for a period of 8 weeks whilst continuing to follow their normal eating patterns. This measure alone led to weight loss of 1.4kg and a 0.6 point reduction in BMI.

Finally, a study[71] of over 18,000 people concluded that increased water consumption generally is associated with eating fewer calories (together with sugar, cholesterol and salt). The researchers found that an increase in water consumption of between 1 and 3 cups per day was linked to a decrease in daily calorie intake of 69-206 calories.

Interestingly, the opposite occurs when people drink sugary drinks. For example, a study[72] gave participants either 450 calories a day of jelly beans or 450 calories of sugary drink and found that the jelly bean group naturally compensated by consuming 450 calories fewer each day but the sugary drink group did not. This resulted in significant additional calorie consumption.

Based on the above it makes sense to start drinking 500ml of water 30 minutes prior to each meal.

Smaller plates and bowls: the size of the plates and bowls we eat from seems to have an effect on the amount of food we eat. If we choose smaller plates we serve ourselves less food and therefore consume fewer calories. The opposite also seems to be true: if we use larger plates we serve ourselves more food and consume more calories. The cause of this is not simply that we can fit less food on a smaller plate and more food on a larger plate, it seems to be caused by an optical illusion with the fancy name “Delboeuf illusion”. This is best explained by the following image:

Small plates and bowls

Which of the two grey circles is larger? You may have guessed from the introduction that this is a trick question. The answer is neither. They are actually both the same size but the first circle seems much smaller than the second. Now imagine how this would translate to when we are serving food. The same amount of food served on a smaller plate would seem to be more than when served on a larger plate.

It is also interesting to note that being aware of this optical illusion is not in itself enough to stop our brains being affected by it[73]. For example, in a study[74] involving a group of HR managers attending a seminar on creating healthy organisations participants were given an hour-long session on how plate size can affect portions. Afterwards they were given a buffet lunch. Those who received larger plates served themselves twice as much as those with smaller plates!

A review[75] of over 50 studies on the effect of smaller plate sizes on portion control concluded that eating from smaller plate sizes leads to a 30% reduction in the amount of food consumed.

It is not just when we eat from plates that overeating issues arise. For example, in a study[76] of cinema-goers researchers gave free stale(!) popcorn to people who had eaten lunch before going into the theatre. Eating lunch first was important as it eliminated hunger as a variable. Some of the participants were given popcorn in a medium size bucket and some were given popcorn in a large bucket. Even though the participants were not hungry and the popcorn was stale those given the large bucket ate 51% more than those given the medium bucket!

The conclusion then is fairly straightforward: choose small plates and bowls and opt for smaller container sizes when out and about.

Energy density of food: not a very catchy heading but it gets straight to the point. Research has shown that we tend to eat a similar weight of food per day, irrespective of the calorie content (also known as “energy density”) of that food[77]. So, by consuming foods that are less energy dense we will consume fewer calories and avoid overeating.

One of the issues with traditional “dieting” – I am trying to avoid using this word because of its negative connotations – is that calories are cut in such a way that people feel hungry. This hunger then makes it very difficult for people to stick to the diet. One of the benefits of consuming foods that have lower energy densities is that you can eat the same amount of food so you do not feel hungry[78] [79]. In fact, if you significantly ramp up your vegetable intake you can eat more food and still consume fewer calories[80].

How does eating food with lower energy densities impact weight management? Clearly by eating fewer calories we can expect a positive benefit. Studies[81] have shown that normal weight individuals tend to consume more low energy density foods than obese individuals. The reverse is also true: individuals that eat higher energy density foods tend to have higher BMIs[82].

Finally, a study[83] in which participants were given a low energy density soup as part of their meals demonstrates how powerful this approach can be to fat loss. In this study participants were given either a broth-based soup to eat before two meals each day or a dry snack to eat before the meals. The soup and the dry snack contained the same number of calories but the soup weighed more. At the end of the study the group consuming the soup lost 7.2kg compared to only 4.8kg in the dry snack group.

The best (and healthiest) way to lower the energy density of the foods we eat is to add more fresh fruit (rather than dried fruit which has less water and so is more energy dense) and vegetables to our meals and to swap high calorie snacks with fresh fruit. There are a number of ways to do this. At meal times we can have a salad prior to our meal or as a side dish, we can add servings of vegetables on the side of the meal or, if vegetables aren’t your thing, you can incorporate them in the meal itself to disguise the taste but still enjoy the benefits.

Exercise: exercise is an important part of any fat loss plan. It can turbocharge both our fat loss efforts and also increase our chances of success with IVF, if done correctly. It is a big subject so I have dedicated an entire section of the Plan to it. Take time to read it through and then decide with your doctor if exercise will be beneficial for you (it will be for most).

Track your progress: research has shown that regularly tracking progress towards any goal, but particularly fat loss goals, significantly improves our chances of achieving the goal. On top of this, a large meta-analysis[84] that reviewed the results of 138 smaller studies involving a total of 19,951 participants found not only that monitoring progress increases the likelihood of goal attainment but that recording progress and sharing it with others improved things further.

You don’t need to go overboard but a weekly weigh-in, measurement of waist, hips and a thigh or using a body fat monitor can be very helpful. Write the results down each week and share them with others and you should see improved results.

Underweight

It is fair to say that most people who are not within the ideal BMI range are above the range and so are looking to lose weight rather than being below it and looking to gain weight. However, as we saw above, being underweight can negatively impact chances of IVF success to a similar extent as being overweight. For this reason, if you are underweight it would be wise to take steps to address the situation.

One way of gaining weight is simply to add a couple of doughnuts to your daily food intake and you will find yourself gaining weight in no time…! Fortunately, there is a better way.

When I talk about gaining weight I should be clear on what I mean. Stuffing ourselves with fast food may lead to weight gain but it will very likely just make us fat. As we have seen fast food is typically loaded with grains, sugars and trans fats so it may also damage our health and consequently our chances of having a baby. We should avoid this at all costs.

Instead, we can add some energy-dense, high quality foods to our diet to increase our intake of calories, mainly in the form of protein and healthy fats. We can eat the same foods from the MDWT but consume a little more and emphasise certain foods.

With your doctor’s consent try a combination of the following:

  1. eat protein at the upper end of the range discussed in Tweak 4 of the MDWT (25-35%). It may seem strange to talk about eating more protein as a measure to both lose fat and gain weight but studies have shown that consuming more protein helps ensure that additional calories are turned into lean tissue rather than fat[85]
  2. serve yourself slightly more food at each meal. If that is a struggle choose larger plates at mealtimes to take advantage of the Delboeuf illusion (see section on plate sizes above)
  3. add a tablespoon of extra virgin olive oil to salads, vegetables and other foods
  4. snack on raw nuts, seeds and dried fruit
  5. follow a weight training programme such as the one set out in Section Six: Fitness 
  6. add a protein shake made from whey protein isolate each day
  7. where you can, eat the protein and fat parts of a meal before the vegetables (but don’t neglect the vegetables!)
  8. eat a tablespoon of virgin coconut oil each day

Resources

Overweight

If you are overweight there is a lot you can do and, unless you have a medical condition that impacts your bodyweight, losing “weight” is completely within your control.

Diet

To lose fat follow a Mediterranean diet. The traditional Mediterranean diet is not perfect and the tweaks set out in Section Two: Nutrition are helpful not just from an IVF perspective, they are also helpful from a fat loss perspective. So, to lose fat follow the MDWT.

Breakfast

Test your tolerance to carbohydrates by trying this experiment: for a week consume 1-2 pieces of white toast with jam or honey at your normal breakfast time and note the time that you start to feel hungry again. Also note down whether you feel tired or energised, calm or irritable. For the next week have a breakfast of meat and nuts at the same time. About 80-100 grams of lean meat of your choice and a handful of raw nuts with the skin on is about right. Again, note down the time you begin to feel hungry and whether you feel tired or energised, calm or irritable. If your body does not tolerate carbohydrates well it is likely that you will see a marked difference in the results. You should feel fuller for longer, more energised and calmer with the meat and nuts breakfast. You should also find that you do not crave carbohydrate-heavy foods as much.

If you are allergic to nuts then you can substitute them for certain fruits that have been shown to cause slow rises in blood sugar levels. Not all fruits do this so stick to the following: berries, apricots, peaches, nectarines, plums and grapefruit. Even if you are not allergic to nuts be sure to rotate the type every few days to prevent food intolerances developing.

Eat More Protein

How much protein should you consume? Tweak 4 of Section Two: Nutrition gives us the answer. The same amount of protein per day both improves our chances of success with IVF and gives us fat loss benefits. Aim to consume between 25% and 35% of your calories as good quality protein each day.

Motivation

Your motivations should already be clear: an ideal BMI will help maximise your chances of having a baby. This will most likely be the most powerful motivating force available to you and the goal setting principles contained in Section One: Our Minds also apply here. You can use them to create a sub-goal of achieving an ideal BMI as part of the overall goal of having a child.

Another motivation tool is to take photographs of yourself from the front back and sides at the start of the fat loss phase and then take further photographs every few weeks until you have achieved your aim. 

Chewing Food Properly

Chewing food properly leads to consuming fewer calories and in turn helps us lose fat. Simply chew each mouthful until it is liquefied before swallowing. This will take some conscious thought to start with but will soon become a habit. You can make the transition easier by following a few simple rules:

– set aside time to eat, don’t eat in a hurry

– try to eat in a calm environment

– be mindful when eating. Put away your phone, tablet, laptop, etc and turn off the TV!

– take smaller bites

– put your cutlery down between each mouthful

– chew until the food is a puree and finish one mouthful completely before moving on to the next

Drinking Water Before Meals

Drinking 500ml of cold water 30 minutes prior to each meal helps prevent over-eating.

Smaller Plates and Bowls

Choose small plates and bowls and opt for smaller container sizes when out and about to prevent over-consumption.

Energy Density of Food

Eat more foods that have fewer calories. The best (and healthiest) way to do this is to add more fresh fruit (rather than dried fruit which has less water and so is more energy dense) and vegetables to your meals and to swap high calorie snacks with fresh fruit. For example, at meal times we can have a salad first or as a side dish, we can add servings of vegetables on the side of the meal or, if vegetables aren’t your thing, you can incorporate them in the meal itself to disguise the taste.

Exercise

Exercise in accordance with the suggestions contained in Section Six: Fitness.

Track Your Progress

Monitoring progress increases the likelihood of goal attainment. Recording progress and sharing it with others improves things further. You don’t need to go overboard but a weekly weigh-in, measurement of waist, hips and a thigh or using a body fat monitor can be very helpful. Write the results down each week and share them with others and you should see improved results.

Underweight

If you are underweight, with your doctor’s consent, you can try a combination of the following to gain healthy weight:

– eat protein at the upper end of the range discussed in Tweak 4 of the Section Two: Nutrition (25-35% of daily calories)

– serve yourself slightly more food at each meal. If that is a struggle choose larger plates at mealtimes to take advantage of the Delboeuf illusion

– add a tablespoon of extra virgin olive oil to salads, vegetables and other foods

– snack on raw nuts, seeds and dried fruit

– follow a weight training programme such as the one set out in Section Six: Fitness

– add a protein shake made from whey protein isolate each day

– where you can, eat the protein and fat parts of a meal before the vegetables (but don’t neglect the vegetables!)

– eat a tablespoon of virgin coconut oil each day

[1] Managing Overweight and Obesity in Adults: Systematic Evidence Review from the Obesity Expert Panel. Us Dept of Health and Human Services, National Heart Lung and Blood Institute, 2013

[2] Body-mass index and risk of 22 specific cancers: a population-based cohort study of 5.24 million UK adults. Lancet. 2014 Aug 30;384(9945):755-65

[3] The Effects of Obesity, Smoking, and Problem Drinking on Chronic Medical Problems and Health Care Costs. HealthAffairs 2002;21(2):245–253

[4] Does Obesity Contribute as Much to Morbidity As Poverty or Smoking? Public Health.2001;115:229–29

[5] Health Survey for England – 2007: Healthy lifestyles: knowledge, attitudes and behaviour, 16 December 2008

[6] Prevalence of overweight and obesity in the United States, 1999-2004. JAMA. 2006;295:1549–55

[7] Does obesity increase the risk of miscarriage in spontaneous conception: a systematic review. Semin Reprod Med. 2011 Nov; 29(6):507-13

[8] Maternal obesity and risk of stillbirth: a metaanalysis. Am J Obstet Gynecol. 2007 Sep; 197(3):223-8

[9] Maternal overweight and obesity and the risk of congenital anomalies: a systematic review and meta-analysis. JAMA. 2009 Feb 11; 301(6):636-50

[10] Obstetric outcomes after in vitro fertilization in obese and morbidly obese women. Obstet Gynecol. 2006 Jul; 108(1):61-9

[11] Effect of body mass index on IVF treatment outcome: an updated systematic review and meta-analysis. Reprod Biomed Online. 2011 Oct; 23(4):421-39

[12] Subfecundity in overweight and obese couples. Hum Reprod 22: 1634-1637

[13] Men’s body mass index and infertility. Hum Reprod Oxf Engl 22: 2488-2493

[14] Reduced fertility among overweight and obese men. Epidemiol Camb Mass 17: 520-523

[15] BMI in relation to sperm count: an updated systematic review and collaborative meta-analysis. Hum Reprod Update. 2013;19(3):221-231

[16] The relationship between male BMI and waist circumference on semen quality: data from the LIFE study. Hum Reprod. 2014;29(2):193-200

[17] Effect of overweight and obesity on assisted reproductive technology – A systematic review. Hum Reprod Update. 2007;13:433–44

[18] Obesity and Reproductive Health. London: RCOG Press; 2007. pp. 175–9

[19] Overweight and obesity negatively affect the outcomes of ovarian stimulation and invitro fertilisation: A cohort study of 2628 Chinese women. Gynecological Endocrinology. 2010;26:325–32

[20] Morbid obesity is associated with lower clinical pregnancy rates after in vitro fertilization in women with polycystic ovary syndrome. Fertil Steril. 2009;92:256–61

[21] Overweight and obesity negatively affect the outcomes of ovarian stimulation and invitro fertilisation: A cohort study of 2628 Chinese women. Gynecological Endocrinology. 2010;26:325–32

[22] Effect of overweight and obesity on assisted reproductive technology – A systematic review. Hum Reprod Update. 2007;13:433–44

[23] The influence of body mass index on in vitro fertilization outcome. Int J Gynecol Obstet. 2009;104:53–5

[24] Fertility Centers of New England, 2008 Annual Conference, American Society for Reproductive Medicine

[25] Effect of overweight and obesity on assisted reproductive technology – A systematic review. Hum Reprod Update. 2007;13:433–44

[26] Effect of overweight and obesity on assisted reproductive technology – A systematic review. Hum Reprod Update. 2007;13:433–44

[27] The effect of body mass index on the outcomes of first assisted reproductive technology cycles. Fertil Steril. 2012 Jul; 98(1):102-8

[28] Male adiposity impairs clinical pregnancy rate by in vitro fertilization without affecting day 3 embryo quality. Obesity (Silver Spring). 2013 Aug;21(8):1608-12

[29] Overweight Men: clinical pregnancy after ART is decreased in IVF but not in ICSI cycles. J Assist Reprod Genet (2010) 27: 539

[30] Risk of ovulatory infertility in relation to body weight. Fertil Steril. 1988 Nov; 50(5):721-6.

[31] Advanced Fertility Centre of Chicago, 2011 Annual Conference, American Society for Reproductive Medicine

[32] Impact of overweight and underweight on IVF treatment in Chinese women. Gynecol Endocrinol. 2010 Jun;26(6):416-22

[33] Body mass index in relation to semen quality and reproductive hormones among 1,558 Danish men. Fertil Steril. 2004 Oct;82(4):863-70

[34] An exploration of the association between male body mass index and semen quality. Reprod Biomed Online. 2011;23:717–723

[35] Fertility problems: assessment and treatment, Clinical Guideline, National Institute of Clinical Excellence, 20 February 2013

[36] Reproductive failure in women who practice weight control. Fertil Steril 37:373. 1982

[37] Weight loss results in significant improvement in pregnancy and ovulation rates in anovulatory obese women. Hum Reprod. 1995;10(10):2705-2712

[38] Body mass index and short-term weight change in relation to treatment outcomes in women undergoing assisted reproduction. Fertil Steril. 2012;98(1):109-116

[39] Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet. N Engl J Med 2008; 359:229-241

[40] Effect of a high-fat Mediterranean diet on bodyweight and waist circumference: a prespecified secondary outcomes analysis of the PREDIMED randomised controlled trial. The Lancet Diabetes & Endocrinology , Volume 4 , Issue 8 , 666 – 676

[41] Ghrelin and glucagon-like peptide 1 concentrations, 24-h satiety, and energy and substrate metabolism during a high-protein diet and measured in a respiration chamber. Am J Clin Nutr 2006; 83: 89–94

[42] Effects of acute and chronic protein intake on metabolism, appetite, and ghrelin during weight loss. Obesity (Silver Spring, Md) 2007; 15: 1215–1225

[43] Additional protein intake limits weight regain after weight loss in humans. Br J Nutr 2005

[44] Increased dietary protein consumed at breakfast leads to an initial and sustained feeling of fullness during energy restriction compared to other meal times. Br J Nutr 2009; 101: 798–803

[45] Variation in the effects of three different breakfast meals on subjective satiety and subsequent intake of energy at lunch and evening meal. Eur J Nutr. 2013 Jun;52(4):1353-9

[46] Ghrelin and glucagon-like peptide 1 concentrations, 24-h satiety, and energy and substrate metabolism during a high-protein diet and measured in a respiration chamber. Am J Clin Nutr. 2006 Jan;83(1):89-94

[47] Critical role for peptide YY in protein-mediated satiation and body-weight regulation. Cell Metab. 2006 Sep;4(3):223-33

[48] Diet induced thermogenesis. Nutr Metab (Lond). 2004; 1: 5

[49] Postprandial thermogenesis is increased 100% on a high-protein, low-fat diet versus a high-carbohydrate, low-fat diet in healthy, young women. J Am Coll Nutr. 2002 Feb;21(1):55-61

[50] Gluconeogenesis and energy expenditure after a high-protein, carbohydrate-free diet. Am J Clin Nutr. 2009 Sep;90(3):519-26

[51] A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Am J Clin Nutr July 2005

vol. 82 no. 1 41-48

[52] The effects of consuming frequent, higher protein meals on appetite and satiety during weight loss in overweight/obese men. Obesity (Silver Spring). 2011 Apr;19(4):818-24

[53] Effect of normal-fat diets, either medium or high in protein, on body weight in overweight subjects: a randomised 1-year trial. Int J Obes Relat Metab Disord. 2004 Oct;28(10):1283-90

[54] The effects of high protein diets on thermogenesis, satiety and weight loss: a critical review. J Am Coll Nutr. 2004 Oct;23(5):373-85

[55] Quality protein intake is inversely related with abdominal fat. Nutrition & Metabolism20129:5

[56] Adherence to an overweight and obesity treatment: how to motivate a patient? PeerJ. 2014 Jul 29;2:e495

[57] Slower eating speed lowers energy intake in normal-weight but not overweight/obese subjects. J Acad Nutr Diet. 2014 Mar;114(3):393-402

[58] Increasing the Number of Chews before Swallowing Reduces Meal Size in Normal-Weight, Overweight, and Obese Adults. J Acad Nutr Diet. 2014 Jun;114(6):926-31

[59] Eating Slowly Increases the Postprandial Response of the Anorexigenic Gut Hormones, Peptide YY and Glucagon-Like Peptide-1. J Clin Endocrinol Metab. 2010 Jan;95(1):333-7

[60] Mastication and Risk for Diabetes in a Japanese Population: A Cross-Sectional Study. PLoS One. 2013 Jun 5;8(6):e64113

[61] Prolonged chewing at lunch decreases later snack intake. Appetite. 2013 Mar;62:91-5

[62] Mastication of almonds: effects of lipid bioaccessibility, appetite, and hormone response. Am J Clin Nutr. 2009 Mar;89(3):794-800

[63] Improvement in chewing activity reduces energy intake in one meal and modulates plasma gut hormone concentrations in obese and lean young Chinese men. Am J Clin Nutr. 2011 Sep;94(3):709-16

[64] Eating Slowly Led to Decreases in Energy Intake within Meals in Healthy Women. Journal of the American Dietetic Association, volume 108, Issue 7, July 2008, Pages 1186–1191

[65] The joint impact on being overweight of self reported behaviours of eating quickly and eating until full: cross sectional survey. BMJ. 2008 Oct 21;337:a2002

[66] Water-induced thermogenesis. J Clin Endocrinol Metab. 2003 Dec;88(12):6015-9

[67] Water drinking induces thermogenesis through osmosensitive mechanisms. J Clin Endocrinol Metab. 2007 Aug;92(8):3334-7

[68] Water consumption reduces energy intake at a breakfast meal in obese older adults. J Am Diet Assoc. 2008 Jul;108(7):1236-9

[69] Water consumption increases weight loss during a hypocaloric diet intervention in middle-aged and older adults. Obesity (Silver Spring). 2010 Feb;18(2):300-7

[70] Effect of ‘water induced thermogenesis’ on body weight, body mass index and body composition of overweight subjects. J Clin Diagn Res. 2013 Sep;7(9):1894-6

[71] Plain water consumption in relation to energy intake and diet quality among US adults, 2005–2012. J Hum Nutr Diet. 29, 624–632

[72] Liquid versus solid carbohydrate: effects on food intake and body weight. Int J Obes Relat Metab Disord. 2000 Jun; 24(6):794-800

[73] Plate Size and Color Suggestibility: The Delboeuf Illusion’s Bias on Serving and Eating Behavior. Journal of Consumer Research Vol. 39, No. 2 (August 2012), pp. 215-228

[74] Portion Size Me: Plate-Size Induced Consumption Norms and Win-Win Solutions for Reducing Food Intake and Waste. Journal of Experimental Psychology: Applied 19 (4): 320–32

[75] Whether smaller plates reduce consumption depends on who’s serving and who’s looking: a meta-analysis. The Journal of the Association for Consumer Research, January 2016

[76] At the movies: How external cues and perceived taste impact consumption volume. Food Qual Preference. 2001;12:69-74

[77] Energy density of foods affects energy intake in normal-weight women. Am J Clin Nutr March 1998

vol. 67 no. 3 412-420

[78] Salad and satiety: energy density and portion size of a first course salad affect energy intake at lunch. Journal of the American Dietetic Association 2004;104:1570-1576

[79] Water incorporated into a food

but not served with a food decreases energy intake in lean women. American Journal of Clinical Nutrition 1999;70:448-455

[80] A diet reduced in energy density results in greater weight loss than a diet reduced in fat. Obesity Research

2004;12:A23

[81] Dietary energy density is associated with energy intake and weight status in US adults. Am JClin Nutr 2006;83:1362-8

[82] Energy density of diets reported by American adults: association with food group intake, nutrient intake, and body weight. Int J Obes (Lond) 2005;29:950-6

[83] Provision of foods differing in energy density affects long-term weight loss. Obesity Research 2005;13:1052-1060

[84] Does monitoring goal progress promote goal attainment? A meta-analysis of the experimental evidence. Psychol Bull. 2016 Feb;142(2):198-229

[85] Effect of Dietary Protein Content on Weight Gain, Energy Expenditure, and Body Composition During Overeating A Randomized Controlled Trial. JAMA. 2012;307(1):47-55