Monday, 23 July 2007
A (retired) chemist's view of diets.
The sedentary life has not been kind to me; too little exercise and too much temptation. So the need to reverse the trend has been faced and things are moving along in the right direction.
A few thoughts on dieting from a chemist's perspective:
1. To a chemist a diet is a simple issue of a mass or energy balance. Your body needs a certain amount of food per day. If you eat more than that, the excess will be stored as fat. If you eat less than that, fat (or protein) reserves will be drawn on to make up the difference.
That's it really.
You can mess around with low carbohydrates, proteins and fruits, grapefruit or whatever but you cannot avoid the simple truth of an energy balance.
If you eat more than you need, you store the balance.
2. Some people say that they cannot lose weight. They have low metabolism. Really? If I locked them in a room with nothing but water would they waste away and die? Yes, of course they would. Therefore there must be a point, somewhere between zero and present intake that is the right amount for them.
No fat people came out of Auschwitz.
3. The local chemist had a sign up "Lose 10kg in a month". Tricky. For a male, the recommended daily maintenance diet is 10,600kJ (2,535Cal). One gram of fat is equivalent to 37kJ. Therefore 10,600kJ is equivalent to 286g of fat. So if you fasted for a 31 day month you could expect to lose 8.9kg of fat. But no-one is going to fast for that long. So the whole thing is a sham.
4. I remember once being told that hard-boiled eggs were best diet food because your use more energy to metabolise them than they actually contain. Also tricky. This means that if I locked you in a room with nothing but water and hard boiled eggs you would starve to death.
I don't think so.