The French Diet - Theory, Practice, and Considerations

Over the last 50 years the fat content of foods has gone down. In spite of this, the incidence of obesity has increased 400%, and has now spread to children and in some cases even infants.

Some experts have linked this problem not to fats but to carbohydrates. They've proposed the theory of the Glycemic Index as a way to predict the potential of some foods to cause weight gain. Now diet expert Michel Montignac has used this concept as the basis for what he calls "The French Diet," which he says is not only a way to lose weight but also a way to promote heart health and reduce the risk of diabetes.

How does the French Diet work? And can it do what it proposes?

The theory behind the French Diet
Montignac believes that people gain weight when they eat too many carbohydrates - specifically those with a high Glycemic Index (GI). The Glycemic Index is a measurement of a food's ability to raise the blood sugar. High-glycemic foods can take the blood sugar much higher than foods with a low Glycemic Index.

When the blood sugar goes higher than normal, the body will usually start a process that results in the release of insulin. This insulin will cause the blood sugar to fall to normal levels. But when too many high-glycemic foods are consumed over too long a period of time, the body can develop "insulin resistance." It can have trouble recognizing the presence of insulin, and as a result the blood sugar won't go down. This causes the release of even more insulin, raising the level of insulin resistance and perpetuating the cycle.

What does this have to do with weight gain? Well, according to Montignac, increased levels of insulin will do two things. They'll facilitate the action of an enzyme called lipoprotein lipase, which causes fat to be stored in the body as triglycerides. They'll also impede the action of another enzyme, triglyceride lipase, which has the opposite effect, causing the breakdown of fat so it can be excreted from the body. So having too much insulin - from eating too many high-glycemic carbohydrates - can actually cause the body to store fats - and gain weight.

Low-glycemic carbohydrates, on the other hand, will raise the body's insulin level just enough for it to do its job - lowering the blood sugar - while still allowing triglyceride lipase to do its job of breaking down fats. And they'll have two other benefits - the lower triglyceride levels will be good for the heart, and the decreased insulin resistance can help prevent type 2 diabetes.

The theory in practice - how the "French Diet" works
Montignac doesn't like to use the word "diet" because he believes it has negative connotations, like restricting how much you eat. His program does have restrictions, but they're more focused on quality than quantity.

The Montignac diet has two phases. The first, the weight loss phase, restricts carbohydrates to those with a low Glycemic Index. Once the desired amount of weight has been lost, the second phase, that of weight maintenance, begins. In this phase, some high-glycemic foods are allowed, but in small quantities, and they must always be eaten with low-glycemic foods.

Montignac carries the idea of food combining a bit further. According to his diet, it's acceptable to eat proteins and carbohydrates, or proteins and fats, at the same meal. But fats and carbohydrates must never be consumed together. He believes that what you choose to eat is more important than how much you eat.

Other opinions
Nutritional experts seem to be have mixed opinions about Montignac's program. They do agree that people who are overweight eat more refined sugars (which would be high-glycemic) and fats than others do. But they're not sure whether a diet high in carbohydrates causes weight gain or weight loss.

They do say that the Glycemic Index, while not worthless, can be hard to pin down because it can change depending on how fresh a food is, how it's cooked, and how long it's cooked for. There's even some variation depending on the individual consuming the food. But they do feel that low-glycemic foods are healthier, because they have more vitamins and minerals and are higher in fiber.

There is concern about the amount of protein recommended by the French Diet. This level, which averages 25%, is higher than what's usually recommended, and there is currently no research on the long-term effects of a high-protein diet.

There's also concern about the emotional aspects of weight loss. Montignac has said that it's possible to lose weight on his program without exercising. Nutritionists believe this may cause people to think they don't need to exercise at all - even though exercise has been proven to have a lot of benefits even when it's not part of a weight-loss program.

On the other hand, because the French Diet doesn't restrict quantities, it may help people feel less deprived. This should help keep them from obsessing about food, and may help them stay on the diet longer.

Does it work?
Montignac would rather call his program a lifestyle than a diet. But whatever you call it, the proof is in whether people can lose weight by following it - and whether they can stay healthy, or become healthier, in the process. A study at Quebec University about six years ago did show a significant drop in the blood level of triglycerides of people who'd been on the French Diet only about a week. This is certainly good news for people with heart problems.

As for weight loss - well, there are people who have lost weight with this type of program. But it can be a hard area to study scientifically because of all the variables involved. And research into its long-term effects would require that people stay on the diet for an extended period of time - something that can be difficult for a lot of people, although it's what Montignac proposes.

Anyone with a serious disease or chronic condition who wants to start a weight-loss program should always talk to their physician first. Program's like Montignac's, which focus on the kinds of foods to eat and to avoid, can have a significant effect on the body's metabolism. Even though losing weight can be really beneficial, especially for the very obese, it's always wise to get a doctor's approval before beginning. Then you'll know that you've made the right choice, and you'll have a better chance of success.