I’ve always been suspicious of the “calories-in-calories-out” theory of weight loss, as I just wouldn’t accept that 400 calories of Sugar Puffs could have the same effect on my body as 400 calories of kale. So I was especially interested to see a book published recently titled The Calorie Myth. (1)
Written by Jonathan Bailor, it’s the result of more than 10 years of investigation, and contains a very satisfying collection of references to research papers. Bailor proposes that the amount of fat we carry on our bodies doesn’t depend on the quantity of calories we eat as much as the quality of the food those calories came from. He describes four factors to support and expand on this theory:
1. Satiety: how much the food fills us up and keeps us feeling full for longer.
Satiety partly depends on protein and fat content, and also the water and fibre content of the food. An example given is that calorie for calorie celery is thirty times the size of gummy bears, so will stretch our stomach and make us feel much more full than sweets will.
2. Aggression: how likely the food we eat is going to be stored as fat, which very largely depends on the speed and amount of glucose released into the bloodstream (glycemic index).
There are a mere 40 calories of glucose in your blood stream at any given time, so any time you eat food that creates more than that, insulin is released in order to keep the level down to the acceptable range. The insulin does that by moving the excess into your fat cells.
3. Nutrition: nutrient quality is described in terms of nutrients per calorie.
Taking fibre as an example, 250 calories of whole grains contain 6 grams of fibre, while the same calorie content of non-starchy vegetables contain 46 grams. That’s a huge difference and worth noting for anyone who a) thinks grains are a good source of fibre, b) suffers from constipation, or c) both of these.
Bailor provides a calorie-for-calorie comparison between wheat and spinach for a wide range of nutrients, from vitamins A, C and K to magnesium, iron and zinc. As you might expect, wheat doesn’t fare well.
4. Efficiency: the fourth factor to consider over merely counting calories is the amount of calories in any particular food that’s going to be stored as fat.
Basically, calories from starch are twice as efficient at being converted into body fat as calories from protein.