On The First Law of Thermodynamics

From the British Medical Journal

Author: Barry Groves, Independent Researcher OX7 6LP

Weight loss on a low-carb diet has two components:

1. Reducing carb (and protein if necessary) intake so that the body no longer has a ready supply of glucose.

2. Increasing fat intake to supply an alternative energy supply.

The aim is to get the body to burn fats -- and crucially for weight loss, this includes body fats. The body will only do this in two circumstances:

1. Starvation (including low-calorie dieting)

2. When glucose is restricted by other means and fats are the only fuel supply available (low-carb, high-fat diets).

But what about the Laws of Thermodynamics?

The laws of thermodynamics, so often quoted by 'experts' (I have another word for them: 'ignorants') in support of the 'calories in = calories out' hypothesis, is a complete red herring as it takes no account of the way the body deals with different nutrients.

One major flaw in their argument is that the body does not use all the food we eat to provide energy. The primary function of dietary proteins, for example, is body cell manufacture and repair: making skin, blood, hair, and finger- and toe-nails, enzymes, etc. The amount of protein needed for this purpose is generally accepted to be about one gram per kilogram of lean body weight. As meats contain approximately 23 grams of protein per 100 grams, a person weighing, say, 70 kg (154 lbs) needs to eat about 300 g (11 oz) of meat, or its equivalent, every day just to supply his basic protein needs. Even eating this volume of lean chicken would provide some 465 kcals. These calories are not used to supply energy, they contribute nothing to the body's calorie needs and so must be deducted if you are counting calories.

Much of the fat we eat is also used to provide materials used by the body in processes other than the production of energy: the manufacture of body cell membranes, bile acids, hormones, the essential fatty acids for the brain and nervous system, and so on. All these must be deducted as well. Thus trying to determine, from food intake and energy expenditure alone, how much excess energy your body will store as fat will give a completely wrong answer. However, these other factors cannot be measured. Calorie counting, which is the foundation of practically every modern slimming diet, is both totally misleading and a complete waste of time.

There are also other anomolies: A figure often used is that one kilogram of body fat represents about 3500 calories. But according to the United States Department Of Health, Education and Welfare:

'On a high-fat diet, 4703 to 8471 excess calories were required for each kilogram of added weight. On a low carbohydrate VLCD [very low calorie diet], replacing fat calories with 8g/day of equivalent carbohydrate calories reduced weight loss by 1.68kg, corresponding to 3300 calories of carbohydrate/kilogram, possibly 2500 calories per kilogram for carbohydrate alone.'(Department of HEW Publication: NIH 75-708, Government Printing Office, 165-86.)

Are they are saying that it takes 4,703 to 8,471 excess calories of fat to add a kilogram of weight, yet it takes only 2,500 to 3,300 calories of carbohydrate to add the same amount? If so 'a calorie is a calorie is a calorie' is not so meaningful after all: a carbohydrate calorie is obviously much more fattening than a fat calorie. So do calories count? Well, perhaps -- but some don't count half as much as others.

Actually, excess fats aren't stored in the body. Any unused fat calories are excreted in urine and faeces. (Endocrinology 1962; 70: 579. Experientia 1963; 19: 319. Metabolism 1964; 13: 87-97. Proc Soc Exp Biol Med 1964; 115:424. Nature 1964; 201: 924)

There is an emerging scientific consensus that weight control is a highly complex topic and the old ideas that overweight people are lazy gluttons are now realised to be as absurd and insulting as the overweight have always thought they were.

By the way, ketones are derived from fats in food which has been bought and paid for. They are a valuable source of energy for cells that usually use glucose. It makes no sense to create in the body a situation where they are flushed down the lavatory.

Source: British Medical Journal