Losing weight is very easy if you have a lot of will power. Perform some vigorous exercise. The body will burn your fat and you will weigh less. No problem. Well there is a bit of a problem. Your body has evolved over millions of years to make you hungry when you have burnt fat. As soon as you have burnt off the fat your body will try to get you to replace it, and this is a very strong urge. To successfully lose weight by exercise you not only have to do the exercise, you also need to have extremely strong will power. The other approach is to not put the calories in in the first place by dieting. But once again you will be hungry so again you are fighting against deep seated primal instincts. You will need that iron will power again.
I am not really a nutritionist but the consensus does seem to be that exercise and eating less is a good thing and there are some kind of health benefits to it. So if that is what you want, off you go! But I am primarily concerned with appearance rather than health. Does a strict diet and a rigorous work out regime make you more attractive to look at? Nobody has ever been shallow enough to carry out a study like this, so we will have to work on guesses. My first observation is that sports stars are not superattractive compared to other celebrities, and even compared to ordinary people. This doesn’t suggest that lots of exercise makes you more attractive. I have heard anecdotaly that supermodels are prone to self indulgent diets – certainly it is hard to imagine Kate Moss going many days on salad and meusli. I would think that offering Naomi Campbell a carrot juice would risk a mobile shaped imprint on your face. Whatever else we think about very attractive people, iron self control and lack of self indulgence aren’t the first things that spring to mind. No, it seems that exercise and diet are far from obviously linked to looking good. In fact thinking of my friends and acquaintances, there doesn’t seem to be much link between their shape and their exercise level.
Speaking personally, a couple of years ago I switched jobs. Previously I had used to cycle six miles to work. This isn’t possible now so I have lost over a thousand calories of exercise a day. Knowing this I was fully expecting to put a lot of weight on. Four years later, my spare tyre has developed a little, but hardly by the amount that such a big change in exercise would suggest. I am not aware of having changed my diet to accomodate the change in food intake, but clearly I must have done without realising it otherwise I would by now be enormous. In the event I have put on maybe 5lbs, which might simply be due to ageing anyway.
Another personal experience. For the last month I have been experimenting with a raw food diet. This isn’t as radical as it sounds – it just involves including a large amount of fresh fruit and veg and avoiding bread and sugar for the first half of the day. This simple change has lost me those 5lbs I put on and put my belt back a notch to where it was five years ago. I haven’t reduced my total food intake at all. If anything it has gone up. On top of that I haven’t stuck to the diet particularly closely. I had a day when I pigged out on a high carbohydrate buffet all day and have also had a freezer problem that meant a lot of unexpectedly defrosted ready meals had to be eaten. Despite that I have lost a little weight. And despite the really modest nature of my weight loss – about 2% of my body mass – people have commented on the fact that I have lost weight.
We all know someone who can tuck into ice cream and chocolate and never seem to put any weight on. And there are the people who are forever dieting and going to the gym without the slightest sign of them losing any weight. I think I am closer to the second type personally – I have never really put on any weight no matter how much I eat.
What is going on here? It has taken me a while to work it out, but I now I think I know. It seems to be mainly related to hunger. When we need energy our body tells us to eat, and if there is food readily available we eat it. To not eat it takes a huge amount of will power – if you think about it, not eating when you are hungry would have been a really stupid move most of the time humans were evolving. It would have been literally suicidal. It is no wonder we find it hard to resist our natural impulses.
So the thing that is controlling our weight isn’t directly the amount of food we eat. It is the hunger mechanism kicking in and telling us to eat. After exercise, we simply eat more. Dieting is in effect simply starving ourselves. It makes us hungry. As soon as you are hungry you want to eat something, and before long there is a good chance you will succumb. In any case – is any of this going to make us more attractive? Scientific studies have given us information suggesting that a particular waist to hip ratio is considered attractive, but I suspect there is more to it than this. We are very sophisticated creatures with plenty of wiring in our brains. I suspect that what we find attractive is likely to be people who look healthy. I also suspect that people who do succeed in starving themselves into losing weight will not make themselves more attractive in the process, or at any rate not very quickly. Extreme exercise or extreme diet are going to be interpreted by the body as a crisis, and I suspect it has a strategy up its sleeve to keep you alive through this process. This could well mean keeping your energy levels low to conserve them so you burn less fat. I think the aim should be to look well fed, not overfed but not underfed either.
The key is managing your hunger. Your hunger is controlled by the hormone insulin. This monitors the level of glucose in your blood and responds accordingly. Look at this graph from Wikipedia (unfortunately the original data is not referenced – but it still illustrates the point.)
When we eat food the glucose level in our blood goes up. Obvious really – but this graph gives us some really valuable information about how it happens. You get more glucose from food with a high glycemic index. Practically speaking this is food that is either high in sugar, like a bar of chocolate or high in carbohydrate like bread or potatoes. The connection between bread and sugar isn’t maybe obvious. But if you try keeping a bit of bread in your mouth and chewing it for a few minutes you will notice that it starts to taste sweet. So in terms of blood sugar a sandwich is going to raise your blood sugar nearly as quickly as eating a bar of chocolate. The message from this is that eating sugar or carbohydrate rich food will rapidly elevate your blood sugar. But also look at the comparison with the low glycemic index food. This raises the blood sugar much less, but it does it over roughly the same time scale.
How does the insuliin respond to higher blood sugar? It does two things, it starts to squirrel away the surplus energy and it sends to message to stop eating. So if you have eaten a bar of chocolate, about half an hour later you will stop feeling hungry. If you have eaten an apple, or a carrot, much the same will happen. Thirty minutes or so later you have lost interest in food and are doing something else. But what is going on inside you is very different. If you have a lot of glucose in your blood then it is being deposited as fat, or got rid of in some way or other. In fact, the high level of insulin generated by the bar of chocolate is quite likely to deplete your blood sugar more so you are going to feel hungry again sooner. What the graph above is showing that once food gets inside the body it is processed down to its components pretty quickly regardless of the form you ate it in. I can say from personal experience that there is another difference between low glycemic index food like raw carrots and high glycemic index foods like toast. It takes much longer to eat it. I can polish off a 300 calorie sandwich in no time leaving the rest of my lunchbreak free to go shopping, where I might well have another snack. If I pack a couple of sticks of celery, a few carrots, an apple and a banana – it takes a good twenty minutes or even a bit more to chomp through them. Look at the graph above – my blood sugar has reached a peak by this time. I am no longer hungry and I won’t be thinking about food for some time. Typically, not until I am home again in the evening.
I am reminded of what is called the French paradox. The french consume large quantities of fat and regularly drink alcohol. Very few people would accuse the French of being uniterested in food. Why aren’t they all obese and dying of heart attacks? Various theories have been put forward. But the one that hits home to me is that they take a long time over their meals and have smaller portions. The leisurely approach to service in French restaurants is legendery. Could their relative trimness be down simply to taking their time between servings giving their hunger mechanism a chance to kick in? At the other end of the scale you don’t have to be in the US long to notice that they go in for very large portions indeed and the service is excellent – efficient and quick. Too quick maybe? Perhaps this explains the very high levels of obesity in Americans?
So what are the implications of this for getting into the most attractive shape. I suggest that we aim to avoid stressing the body. Don’t indulge in vigorous exercise straight off. If you want to get the health benefits of exercise by all means do so – but build up gradually so your body has time to build the muscles and enzymes it needs. You don’t need to exercise to lose weight or to look better- you just need to balance your energy input with your energy needs. If you are simply concerned with looking better I would forget about exercise altogether. Don’t starve yourself. You might get thinner but you probably won’t look any better. What you need to do is to manage your hunger. When you are hungry you need to eat. But you shouldn’t eat food that is going to release a lot of glucose into your blood stream.
During the day, avoid sugar and carbohydrate. Eat fruit and/or raw vegetables. Don’t skip breakfast or lunch. Do eat something at breaks. If you really must eat processed foods like sweets and chocolates, eat a small portion. This might take willpower. But remember you only need to resist for about half an hour and your body will come to the rescue. You can relax a bit in the evening because you will be going to bed where you have eight hours or so when your body can sort it out. But basically the same rules still apply. Serve small portions, avoid processed foods and foods rich in carbohydrates. Above all, space out your eating to give your hunger a chance to abate.
[hana-code-insert name=’General Interest’ /]
J.Pers Soc Psychol 1993 Aug 65(2) 293-307 Adaptive significance of female physical attractiveness: role of waist-to-hip ratio
Hartz A.J, D.C Rupley and A.A Rimm The association of girth measurements with disease in 32,865 Woemn Am J Epidemiol 1984 Vol 119 No 1:71-80
Dulloo AG, Duret C, Rohrer D, Girardier L, Mensi N, Fathi M, Chantre P, Vandermander J. Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. Am J Clin Nutr 1999; 70: 1040-1045
Bjorntop, P. Adipose tissue distribution and function. International Journal of Obesity 15:67-81, 1991
Pond, C.M. Storage. In Physiological Ecology, C.R. Townsend and P. Calow (Eds.). Sunderland, MA: Sinauer, 1981, pp. 190-219.
Singh, D. Adaptive significance of female physical attractiveness: role of waist-to-hip ratio. Journal of Personality and Social Psychology 65:293-307, 1993
Anderson, J.L., Crawford, C.B., Nadeau, J., and Lindberg, T. Was the Duchess of Windsor right: a cross-cultural review of the socioecology of ideals of female body shape. Ethology and Sociobiology 13:197-227, 1992
Thornhill, R., and Gangestad, S.W. Human fluctuating asymmetry and sexual selection. Paper presented at the Human Behavior and Evolution Society, Ann Arbor, 1994a