Eat Yourself Slim… and Stay Slim!

In the introduction Montignac tells his own story: his father was 1.73 m tall and weighed 120 kg, he himself was a fat child at eight, was teased as a teenager, and as an adult kept gaining weight despite eating little and exercising a lot. Reading scientific papers on diabetes, he noticed that type 2 diabetics improved their blood sugar by eating 'low-glycaemic' carbohydrates, tried the same approach on himself, and lost 16 kg in a few months without limiting quantities — only by choosing differently. The author is not a doctor, one of the most frequent criticisms of the book, though he writes that a team of physicians later gathered around him.

Chapter 1 is the book's most assertive part. Montignac calls the calorie model, which compares the human body to a 'boiler', a 'myth': fat people don't necessarily eat more, athletes can keep the same weight on anything from 2,000 to 6,000 calories, and calorie tables are imprecise. In his view a low-calorie diet triggers a 'survival instinct': the body cuts its spending, regains the lost weight with interest as soon as the diet lapses, and in women even creates new fat cells. A box in the middle of the chapter proclaims in capitals: 'COUNTING CALORIES IS NONSENSE'.

Some of these arguments rest on real observations: a modest slowing of metabolism after weight loss (metabolic adaptation) and the long-term failure of most diets are well documented, and calorie tables really are approximate. But concluding that 'calories don't matter' is scientifically wrong: controlled studies show that weight change is determined mainly by energy balance, while the effect of the glycaemic index is secondary. Charts in the chapter — such as a person eating 1,000 calories who climbs from 90 to 100 kg after a series of diets — are given without sources, and the statistic that 'only 15% of obese people overeat' comes from self-reported surveys in which people tend to under-report what they eat.

The Phase One rules, on the other hand, are practically sensible: eat three meals a day at set times, never skip a meal, avoid snacking, cut out sugary drinks, limit saturated fat in favour of olive and fish oils, eat slowly and chew well, choose wholegrain over white bread. Most of this advice still appears in healthy-eating guidelines today. What is debatable is permitting alcohol even in the weight-loss phase — 'no more than a glass of wine and a glass of beer with each meal' — and the rigid 'allowed/forbidden' fruit lists (for breakfast, bananas and chestnuts, for instance, are on the forbidden list).

In the end, the book matters historically for bringing the glycaemic index to a mass audience, and its message against sugar and white flour is still relevant. But its central theoretical claim — that calories are unimportant — is not supported by current science, and the book should not be used in place of advice from a doctor or dietitian. The Turkish translation is at times stilted.

• A clear two-phase structure with a rules summary at the end of each phase
• Concrete menus and tables for breakfast, lunch and dinner
• The author's personal experience woven together with theoretical explanation