‘When rapid inane approaches to weight loss become prime time juggernauts on television, go figure that’s what people look for in weight loss.’
Dr Yoni Freedhoff, The Diet Fix 1
IT WAS, BY any standards, the ultimate fad diet.
Over a ten-week period Mark Haub, a professor of nutrition from Kansas State University, lost 27 lb by cutting his calories from 2,600 per day to fewer than 1,600. As a result, his weight fell from a little over 14 stone (201 lb) to around 12 stone (174 lb) while his body fat decreased from around 33% to 25%. LDL (‘bad’ cholesterol) fell by 20% while HDL (‘good’ cholesterol) increased by a similar amount. In addition, his triglyceride (a form of fat) profile was reduced by 39%.2
That he lost weight by reducing the number of calories he consumed is hardly surprising. What he ate while doing so created a social media storm.
For more than two months, Professor Haub’s diet consisted largely of Twinkies, brownies, and cupcakes, with between-meal snacks of Doritos, Corn Pops and fudge. A typical daily menu would include: Golden Sponge Cake: (150 calories; 5 grams of fat); Little Debbie Star Crunch (150 calories; 6 grams of fat); Doritos Cool Ranch (75 calories; 4 grams of fat); Kellogg’s Corn Pops (220 calories; 0 grams of fat); whole fat milk (150 calories; 8 grams of fat); Brownie Chewy Fudge (270 calories; 14 grams of fat) and Little Debbie Cake (160 calories; 8 grams of fat). In addition, he ate some canned green beans, baby carrots and a few sticks of celery. He also took a multi-vitamin pill each day and drank a Muscle Milk protein shake.
To a lot of readers this probably seems like a shocking diet. However, far from regarding eating all this junk food as unusual, Haub claimed it was an accurate reflection of what millions of people eat every day. Furthermore, he thinks ‘it’s unrealistic to expect people to totally drop these foods for vegetables and fruits. It may be healthy, but not realistic.’3
We must emphasise that neither we nor Professor Haub are recommending such a diet as a healthy way to lose weight! The long-term consequences of avoiding fruit and vegetables are likely to prove serious. However, what this unusual experiment demonstrates is that when it comes to losing weight, it’s calorie-cutting which matters most. Provided the number of calories you consume remains low, you could just as easily slim by eating pork pies or hamburgers than nibbling on lettuce leaves or nuts. You would just have to ensure that you were eating smaller portions in the case of high-calorie foods. Equally, as we saw in Chapter 9, it is possible to put on weight by eating foods widely considered to be healthy, such as oranges; all you need do is consume enough of them.
Recent years have seen the rise of ‘fad diets’, weight-loss plans which promise dramatic results through beginning a very specific (and usually very limited) diet. They may include some kind of specific ‘miracle’ ingredient, the dieter being told to eat one particular foodstuff in large quantities. They also frequently involve the elimination of a particular macronutrient from the diet, almost always either fat or carbohydrate.
The two differ in energy content, with fat providing the greatest amount, at 9 calories per gram, and carbohydrate approximately 4 calories per gram (which is the same amount as protein).4 The pendulum of fashion swings back and forth between low-carbohydrate versus low-fat diets, with one being favoured, then the other. Each side of the debate has a slew of academic and dietetic researchers proclaiming its health benefits. So, let’s consider the role each plays in our diet to better understand why either one might be considered a candidate for elimination.
During the 1990s, many diets advocated reducing or banning fat due to its high energy content. With what is in fact faulty logic, we believed that eating fat would inevitably make you fat. This is far from the truth – weight gain results from consuming more calories than your body requires, irrespective of whether the food is fatty or not. Yes, eating enough calories in the form of fat will result in weight gain, but the same is true for protein or carbohydrate. Furthermore, at least 20% of our diet must consist of fat, since, without it, fat-soluble vitamins (A, D, E and K) cannot be transported, stored or absorbed.5 So while it tends to get something of a bad press, it is actually essential to have fat as part of a healthy diet. That said, different kinds of fats have different benefits and dangers, which it is worth being aware of.
Typically derived from animal sources such as red meat, poultry and full-fat dairy products, saturated fat raises total blood cholesterol levels and low-density lipoprotein (‘LDL’), raising your risk of developing cardiovascular disease if consumed in excess. Overconsumption of saturated fat has been associated with the development of Type II diabetes.
Although trans fat occurs naturally in some foods, most trans fat occurs in oils that have been partially hydrogenated. Hydrogenation is the process that makes the fat easier to cook with, and also less likely to go bad. This makes it an ideal ingredient in the packaged goods segment, and it has been used in everything from crisps to cakes. However, research has shown trans-fat consumption to be associated with an increase in the risk of developing heart disease, diabetes and perhaps of strokes. It is therefore advisable to consume as little of this type of fat as possible.
Trans fat has been the focus of numerous health campaigns, and the food industry has responded by eliminating trans fats in many of their products; thanks to significant pressure on behalf of the public health community, it is now becoming an industry standard to refrain from using trans fats in foods.
Monounsaturated fats are liquid, but can turn solid when chilled. They have been shown to decrease risk of heart disease, and may benefit insulin levels and blood-sugar control. Olive oil is one of the most famous monounsaturated fats; other examples include avocado, almonds (raw), peanut butter, macadamia nuts, sunflower oil and seeds, and hazelnuts.
Polyunsaturated fats are found primarily in plant-based foods and in oils. They occur in fatty fish such as salmon, mackerel, herring and trout, and also in walnuts and sunflower seeds. They have been shown to improve blood cholesterol levels and reduce the risk of heart disease.
Omega-3 fatty acid plays an essential role in health and must be obtained from our diet, since the body cannot manufacture it. There are three types of omega-3 fatty acid. The first is called alpha-linoleic acid (ALA), the second eicosapentaenoic acid (EPA) and third docosahexaenoic acid (DHA). Fish are the best source of omega-3s; although they can also be obtained from plants, the body does not metabolise these as effectively as it does those from fish sources. Omega-3s help protect against heart disease, control blood clotting and build cell membranes in the brain.
Fad diets that are high in fat fail to take into account the fact that such a diet can wreak havoc on blood lipid levels. It is certainly not the ‘healthiest’ way to eat.6 However, without fats essential functions of the body such as vitamin absorption and protein synthesis cannot be carried out. So while we should certainly be cautious about the amount and kind of fat we eat, we should also realise that fat is not a foe. As with any other element of our diet, the old saying obtains – everything in moderation.
The other food group which fad diets frequently focus upon is carbohydrates. Low-carbohydrate plans can prove wonderfully effective in the short term (i.e. the first six months), but whether they are the best path to maintaining a healthy weight in the long term is questionable.
Carbohydrates can be divided into two broad categories. The first group comprises the simple sugars, glucose, fructose, sucrose (glucose + fructose) and lactose (glucose + lactose).7 These are found in foods such as flour, bread, pasta, some vegetables such as potatoes, and fruits. Once consumed, they enter the bloodstream via the small intestine and travel to the liver, where they are converted into glucose.8 Excess glucose is stored in the liver and skeletal muscles as glycogen. Should the stores become full as a result of overconsumption – they can only hold about 2,000 calories – glycogen will then be stored as fat, resulting in weight gain.
If, on the other hand, there is insufficient glucose in the bloodstream, the body responds by breaking down fat. However, after an extended period of time, the body will begin to rely on breaking down amino acids. By doing so it prevents protein (where amino acids are found) from serving its main purpose of building and maintaining muscle. It also places additional stress on the kidneys as they are obliged to remove excess protein from the blood.9
The second group is the complex carbohydrates: starch and fibre. There are three key components to grains: bran, germ, and endosperm. The bran is the outer shell of the grain, and provides fibre and B vitamins. The germ contains E vitamins and essential fatty acids. Finally, the endosperm contains starch. For this reason, consumption of whole grains (i.e. those that keep the bran and germ) is encouraged as a way to increase consumption of micronutrients and fatty acids.
Fibre comes in two forms, insoluble and soluble. Insoluble fibre is found in the outer coat of whole grains, the stringy bits of celery and the skins of fruit. Soluble fibre is what gives vegetables, fruit, grains and beans a thicker, sometimes gummier texture. It is also present in oatmeal, apple sauce, prunes, beans and lentils. Insoluble fibre regulates gut motility, while soluble fibre lowers blood cholesterol levels. Critically, both types contribute to feelings of fullness after a meal and, because they take significantly longer to digest than simple sugars, offer a more sustained source of energy.
However, as is the case with simple sugars, complex carbohydrates are also converted into glycogen, and if not used by the body are stored as fat. So, the ‘low-fat’ and ‘no-fat’ diets of the 1990s encouraged people to consume grains, bagels and gummy bears to their hearts’ (dis)content. Then, when researchers reported that the insulin-spiking effects of sugar can promote weight gain and fat storage, this type of diet suddenly became significantly less attractive. Moreover, as we learn more about the rewarding effects of the taste of sweetness, and how this is processed in the brain, we are becoming increasingly wary of sugar and related sweetening substances.
So again, a balance needs to be struck: consuming too many carbohydrates of either type will lead to weight gain and fat storage, but failing to consume enough will prevent the body from functioning healthily.
Wheat is a source of both simple sugars and complex carbohydrates and, for many people the world over, wheat-based products are a staple energy source. However, in recent years, two New York Times bestsellers have been devoted to exploiting their supposed evils. Wheat Belly, by cardiologist William Davis, and Grain Brain, by neurologist David Perlmutter, encourage us to believe that a multitude of health problems are due to grain intolerances and allergies.10 But is this really the case?
Davis describes wheat as the ‘perfect Frankengrain’, and accuses it of inflicting more harm than ‘any foreign terrorist group’.11 The sensationalist nature of this assertion aside, there is no doubt that there are some drawbacks to eating wheat. Coeliac disease, a serious medical condition, is relatively widespread and is greatly aggravated by wheat products. A coeliac suffers from an autoimmune reaction to gluten (a protein found in wheat, rye and barley) in their small intestine. This interferes with the absorption of nutrients from food. For a coeliac, even a mouthful of a food containing gluten can produce considerable discomfort, abdominal pain, gas, bloating and constipation. Gluten is not only found in food but also in medicines, vitamins and even lip balms. Recent research also suggests that coeliac disease can lead to far more serious conditions, including anaemia, osteoporosis, sterility, and possibly even cancer.12
Leaving such medical problems aside, it is true that skyrocketing levels of obesity are likely linked to significant increases in the consumption of processed carbohydrates, including wheat. However, in spite of the negative press it has begun to receive, it is hard to see why wheat should be singled out for particular criticism.
Many of the cereals and foods we eat today are hybrids, the result of mixing between different strains. This is sometimes cited as the source of our problems with wheat and corn. Yet the same agricultural process has been carried out for tens of thousands of years without producing today’s skyrocketing levels of obesity. Furthermore, while some people do suffer from food intolerance and food allergies, doctors estimate these afflict only around 1% of the population.13
It seems likely that a significant proportion of those claiming to be ‘gluten intolerant’ are actually experiencing what doctors refer to as ‘gluten avoidance’. Gluten avoiders have stomach problems without knowing why they occur or how best to address the underlying causes. Rather than seeking medical advice, or perhaps being unconvinced by the solutions their physicians offer, they search the Internet and learn about the many so-called ‘benefits’ of going gluten free, rapid weight loss being amongst them.14 This can indeed occur, although most nutritionists suggest the most likely reason for this is a placebo effect – in essence the person modifying their eating behaviour and consuming less because they are following certain dietary restrictions, rather than the particular types of food they are allowed being an effective weight loss regimen in themselves. This is a fairly common occurrence when an individual is embarking on a new diet.15 In recent years gluten-free products have become a food marketer’s dream come true, with a US market value of $4.2 billion. The sector is also projected to grow by 10% until 2018. 16 The range of gluten-free products now extends from pasta to church communion wafers! Even Kellogg’s has jumped on the bandwagon, removing barley malt in order to advertise their classic Rice Krispies are ‘easy for kids to digest’.17 Gluten, and by extension wheat and other cereals that deliver protein (indeed, gluten is a protein), has been blamed for everything from excess tummy fat to mood swings. However, many gluten-free products use rice and tapioca flours, which have little or no nutritional value. They often sit high on the glycaemic index, in addition to being higher in fat and lower in protein, which makes them less satiating.
‘We have a tendency to think that gluten-free is healthier,’ says Toronto-based naturopathic doctor Meghan Walker, but she asserts that, contrary to our expectations, ‘that is certainly not the case.’18 In fact, research shows that adopting a gluten-free diet can result in higher weight gains than following a diet high in protein but low in processed carbohydrate. The unfortunate fact about many gluten-free substitutes is that they are higher in calories – and fat – than the gluten-filled original. A stamp of ‘gluten free’, just like its ‘fat free’ cousin of the past, does not mean a licence to binge.
Just as certain types of fat should be avoided, the same can be said for certain kinds of carbohydrate. Processed carbohydrates and flours stripped of their whole grain shell (white flour), for example, are excellent at delivering calories but offer very little else. White bread is devoid of the health benefits of whole grain because, with the removal of the outer shell from the grain, the insoluble fibre it would otherwise have contained has been lost. Moreover, white flours are also digested quickly, raise blood sugar levels quickly (and so also cause them to drop quickly), and therefore do not have the same satiating benefits as wholegrain options.
More than any other form of carbohydrate, High Fructose Corn Syrup (HFCS) has been blamed for the obesity pandemic. This comes in two forms: HFCS 42, which consists of 42% glucose and has the sweetness of table sugar (sucrose), and the even sweeter HFCS 55, with about 55% fructose, which is mainly used in soft drinks.19 HFCS is produced by refining corn kernels to a point where long chains of glucose are broken down into short chains of fructose. Due to the Farm Bill in America, corn is cheaper than cane sugar in America. This means that many US-manufactured products contain HFCS – the government is in effect encouraging production and consumption of a foodstuff we know contributes to overeating, due to its ultra-sweet taste. However, there is no hidden ingredient in corn that automatically precedes morbid obesity, so a fear of corn itself isn’t really warranted. As we have seen time and again, there are no short-cut answers in the obesity pandemic and, while HFCS and other sugars are undoubtedly a concern, things are not that clear cut.
‘It’s hard to prove that sugars are bad at all because high sugar intakes tend to cluster with other health behaviours,’ explains nutritionist Laura Forbes.20 ‘There are links between corn consumption with obesity and diabetes, in particular, but we are far from having proof of causality. The main point is that high-sugar foods are low in micronutrients and vitamins, have low satiety factors, and ergo may be involved in causing obesity and diabetes. An important rule of thumb is to avoid ultra-sweet foods in general; given their propensity for causing binge eating, it may be best to put away the sweet stuff indefinitely.’21
While the body must expend between 5% and 15% of the energy contained in carbohydrate in order to digest and use it, this figure jumps to between 20% and 35% when it comes to processing protein.22 Furthermore, while the body can store excess carbohydrate energy as glycogen (and excess glycogen as fat) it cannot store excess protein; it has to be processed right away, burning up some energy along the way in a process called thermogenesis.23 So, proteins take more energy for our body to digest and make use of, meaning that caloric intake in the form of protein will actually result in less energy being made available to the body than if the same number of calories was ingested as carbohydrate. And since protein can’t be stored as energy, there is less risk of excess consumption leading to weight gain.
When carbohydrates are largely eliminated from the diet, as described above, the body has to use fat as a source of energy in order to metabolise protein, a process called ketosis. This results in the production of ketones, which further dull the appetite.
On the basis of all this, removing most carbohydrates and significantly increasing the amount of protein we consume sounds like a good idea. Indeed, this is the basis of the famous Atkin’s Diet. But is such an approach really a ‘magic bullet’ resulting in rapid and lasting weight loss?
The answer is both yes and no.
Yes, because such an approach is likely to work in the short term and does indeed cause fat to be consumed. No, because it offers little hope of sustainable weight loss and may compromise our long-term health.24
‘It was once thought that the high protein intakes would help preserve lean body mass, such as muscle, when weight loss happens,’ explains Laura Forbes, ‘but research has shown that not to be the case – lean body mass is still lost in these diets. We also know that in people with poor kidney function, high protein intakes could increase the risk of kidney disease. At present this is more of a hypothesis than something that has solid proof. There’s really no information about its long-term safety or health effects.’25
Thus, it is likely that high protein diets may only work for the first six months of a regime. After that point it may be advisable to slowly reintroduce complex carbohydrates in order to avoid lean body mass being shed along with fat. Since high protein will also put additional stress on renal function and the kidneys, it merits consideration whether this is really a healthy lifestyle to pursue long term.
So, despite people’s belief that low-fat or low-carbohydrate diets are the answer, in fact neither one is a sure-fire route to maintaining a slim body in the long term, and both can have negative impacts upon health. Maintaining a balanced diet that incorporates all the macronutrients is far preferable.
So if there are no short cuts through eating particular kinds of food, we are forced to return to the point made at the beginning of this chapter: that the most important thing one can do to achieve weight reduction is to limit the total amount of calories one consumes. This may not be popular, exciting or new information and therefore probably doesn’t have the appeal of a fad diet, but it is nonetheless true.
The average man requires around 2,500 calories daily and the average woman 2,000. The problem, of course, is that none of us is average! Our actual daily requirements vary according to factors such as weight, age, sex and level of activity. Marines, for example, can eat 5,000 calories a day or more without putting on a pound of additional weight. But then very few people exercise as hard as a marine!
Your basic daily calorie requirement can be calculated using a formula developed by scientist Max Kleiber in 1932:
Calories Required = 38W¾ where W = your weight in pounds
If the prospect of working through an equation like that leaves you cold, you can easily find out how many calories you consume each day from our Fat Planet website (www.thefatplanet.com). On the other hand, if you are not put off by the idea of some basic maths then read on.
To calculate a ¾ power of your weight (W), multiply it (in pounds) by itself three times i.e. W x W x W. Now take the square root of that number, twice. (On a calculator, just hit the 3 button twice). That has given us 1W¾.
Finally, multiply the result by 38, bringing the total to the 38W¾ of Kleiber’s equation. The number on the screen will then be your total recommended calorie count for one day.
Let’s run through an example.
A person weighing 150 lb would multiply this number (W) by itself three times (i.e. raise to the third power) = 150 × 150 × 150 = 3,375,000.
Now take the square root twice. First time = 1,837; Second time = 42.86. Finally multiply this number by 38 (42.86 × 38) = 1,629 calories per day.
Note that this is a basic minimum – it is considerably lower than the average of 2,000 calories for a woman and 2,500 for a man. If you are active, exercise on a regular basis or do hard physical work then your requirements will clearly increase, potentially by a significant amount.
Fad diets represent sensationalised adaptations of scientific theory, which fail to take into account the complexity of our relationship with food. The result, more often than not, is the development of a binge-purge cycle in which the pounds shed are quickly replaced when the dieter gives up and returns to their normal pattern of eating. Then, unhappy with having regained the weight, they begin the fad diet once more – or possibly start a new one – and the process repeats itself.
‘I think people are tempted by crash diets in part because it’s in our nature as a species to want things to happen quickly,’ says Dr Yoni Freedhoff, Canada’s pre-eminent obesity expert and bestselling author of The Diet Fix. ‘In part because that’s what the media and entertainment industries have normalised as the way to do things.’26 We will explain why this is so in the next chapter, where we examine the traps that lie in wait to snare the unwary along the road to sustainable weight loss.