Walking past a primary school in my neighbourhood in Paris, I always look to see what pupils are getting for lunch.
On one day, before the end of last term, I noticed that they had tomato salad, chicken curry with pasta shells, creamy tomme blanche cheese and a compote of apples. The weekly menus, displayed outside the school doors, are colour-coded to indicate nutritional value - orange for protein, green for fruit and vegetables, brown for starchy foods, blue for dairy.
School dinners follow precise nutritional rules to ensure at least one balanced meal a day for France's children. Guidelines established in 2001 specified more fibre, vitamins, iron and calcium, and less fat, salt and sugar. Local authorities are responsible for providing the meals, which are planned by menu committees consisting of council representatives, parents and the company that prepares them. School medical officers or dieticians attend meetings.
Following health scares such as "mad cow" disease and foot-and-mouth, together with a growing trend towards sustainable development, organic ingredients increasingly feature on school menus.
For the past 20 years, the annual Semaine du gout - "Taste Week" - has taught the young about good eating, with chefs visiting schools or inviting pupils to restaurants, demonstrating skills and introducing children to new foods and flavours.
France, a nation that prides itself on the quality of its food, was one of the first European countries to establish a National Programme for Nutritional Health (PNNS). But despite efforts in schools to ensure pupils consume a healthy diet, obesity is rocketing - especially among children. And plump children become fat adults.
A survey of 25,000 people aged over 18, published in November, showed there were now 20 million overweight French adults, of whom 6.5 million were obese - three million more than 12 years ago. And they are getting fat younger.
Nearly one in five children is overweight or obese, and child obesity doubled in the previous decade, according to the 2006 PNNS study. For youngsters from disadvantaged families, the rate soars to 30 per cent.
At the root of the problem are changes in eating habits and lifestyle, which has become more sedentary. The French are eating more, but less healthily, says the Association Francaise de Pediatrie Ambulatoire (AFPA). It blames "cars, lifts, television, computers and video games".
France's food safety agency found that fewer than half of all teenagers between 15 and 17 took even the minimum exercise necessary to maintain health, and just over six out of 10 boys, and fewer than one girl in four, took the recommended hour's daily exercise.
Now the buck has passed to the top. In October, President Sarkozy appointed a commission into the prevention of obesity in all groups. Perhaps a national regime of fresh tomato salad and chicken curry could help restore the nation's waistlines.