|What I Eat - Peter Menzel, Faith D'Aluisio|
Yesterday, I was reading this book with my children, and I was saddened by the ordeal teenagers have to go through in order to lose weight.
The story was about a 15 year old girl who, for the fourth consecutive year, was enrolled in a weight-loss camp during the summer holiday, instead of enjoying herself with family and friends.
A typical menu looks like this (a total of 1700 calories):
- Apple pancakes with sugar free syrup
- Turkey sausage
- Skim milk
- Orange juice from concentrate
- Peanut butter and jelly sandwich: whole bread, reduced-fat peanut butter, sugar-free jam
- Celery and baby carrots
- Fruit salad: oranges, pineapple, coconut, mini marshmallows with yogurt
- Chicken without skin and fat
- Vegetables cooked with margarine
- Salad: lettuce, cabbage, carrot with fat-free Italian dressing
- Whole wheat pasta
- Sugar-free punch drink
- Italian ice
- Chocolate pudding
A total of 1700 calories. But, this is not the point. The quality of the food is more important than the number of calories. Here, Ethan Sims M.D. (University of Vermont) and his overfeeding experiments come to mind.
When he put different groups of people on high-fat or high-carbohydrate diets, and asked his subjects to overeat. He reported that it was very difficult to make the high-fat group swallow 1000 more calories per day, on the other hand the high-carbohydrate diet group had no difficulties in eating even 10,000 calories per day and still feel "hunger late in the day".
The weight-loss results were also surprising. Sims observed that it was impossible to fatten up subjects on a high-fat, high-protein diet. This means that the excess calories do not necessarily mean that we put on weight if these calories come from protein and fat.
If we feel satiety easily on a high-protein, high-fat diet, and feel hunger even if we consume carbohydrates in excess, then this means that insulin (elevated on a high-carbohydrate diet) has a role to play in the physiology of hunger. This is what happens in the body when insulin levels are high:
"High insulin levels [...] prevent the liver from releasing the glucose [sugar] that's stored there as glycogen. As a result. it's glucose that we crave."
- Gary Taubes
So the more carbohydrates we consume, the more our insulin level is elevated, the more glucose is blocked in the liver. The body would like to burn glucose, but has no access to it. So our brain will send us a message to eat more carbohydrates (glucose) to be burnt as energy. So we eat more bread and the circle starts all over again.
This menu (low-fat, high-carbohydrate) from this particular weight-loss camp has two effects:
- Weight-loss by starvation where the subject lose not only fat tissue, but also muscle and organ tissue. Usually, weight comes back after people go off the diet.
- Constant hunger and cravings, which cannot be overcome by discipline and psychotherapy. So overeating is not a psychological disorder and a bad character problem, but a physiological one associated with high insulin levels.