On many food labels there’s a listing for the number of calories per serving, the amount of fat and the number of fat calories. What’s the practical difference between a strictly low-calorie diet, a low-fat diet and a low-fat-calories diet?
It can get very complicated, but in broad terms:
A low calorie diet is just that: low claories. It regulates the amountof energy that a person is taking in through food. It is primarily intended to stabilise or reduce body weight. So long as you take in less energy than you are burning you will lose wieght, regardless of whether those claories come form fat or carbohydrate.
Low fat diets are recommended for most people these days regadless of whether they need or want to lose weight. Fat consumption is correlated with heart disease so the less fat you eat the better it is for your heart (with a few caveats). This is the main reason why the fat content of food is important and why most people are on low fat diets. Low fat diets are often not in any way calorie controlled diets and have no little if any effect on weight loss.
All the low fat, low calorie diets I’ve seen are “Hollywood” fads with no basis in science or even relaity. The only real reason to be concerned with fat consumption in a calorie controlled diet is because it’s a bit easier to gain weight form fat. If your body has to manufacture the weight you gain by converting carbohydrate to fat it’s fiarly inefficient. As a result if you’re gaining weight on a low fat diet you will actually gain less wieght than with an identical calorific intake on ahigh fat diet. However all this is usually academic because the whole point of a low calorie diet is to lose or maintain weight. With no weight being added it doesn’t matter a tinker’s cuss whether the calories come from fat or carbohydrate. If youre on a low calorie diet to lose weight there’s little point worrying about what form those calories are in.
PBS has been replaying “Frontline: Diet Wars” lately, so if you don’t have an episode coming up in your location, watch it online here. It’s an excellent show that will answer that and many other questions you might have.
I think the caveats are quite important. Many fats are actually good for you, and reduce your risk of coronary disease.
Like I said, it can get complicated. Point to relaise here is that even with “good fats” the benefit only applies to small amounts. You can’t just pig out on deep fried foods simply because it was boiled in unsatutrated fats. Eating large amounts of any fat at all (and most Americans do eat large amounts of fat) will increase blood lipid levels and lead to plaque formation.
The dose maketh the poison.