Loren Cordain, a professor at Colorado State University and the author of “The Paleo Diet,” links the movement to a 1985 New England Journal of Medicine article, which proclaimed that the "diet of our remote ancestors may be a reference standard for modern human nutrition."

Another source of paleo converts is CrossFit, a fitness program known for grueling workouts combining weightlifting and gymnastics. CrossFit trainers, who teach at more than 1,200 gyms and other affiliates across the country, generally encourage clients to follow either a caveman diet or the Zone diet, which requires tracking calories. "Some of the gyms have hardcore paleo folks, and if you're a member of that gym then you're paleo, while other gyms are hardcore Zone," said Anthony Budding, who manages the content on CrossFit.com.

Experts in early humans dispute some of the tenets of latter-day paleos, including the belief that fasting is beneficial and that the body is unequipped to handle an agriculture-based diet.

Still, there is a "sharp contrast" between the strength and fitness of our distant ancestors and us, said Clark Larsen, a physical anthropologist at Ohio State University. "The male or female of 12,000 to 15,000 years ago will be considerably stronger and in better shape," he said. Unfortunately, life was short: If you made it to age 30 or so, you had done well.

Tyler Florence is among the chefs who told me they had massively cut down on their meat intake. Even Michael Lomonaco, the chef of the Manhattan steak joint Porter House New York who recently knocked off 10 lb., eats a lot of simply cooked proteins surrounded by vegetables. "I do a slow-roasted salmon--there's no oil, no added fats--roasted on cedarwood in an oven. It's served with big white beans, fresh tomatoes and tarragon," he says. "What a great steak house this is: the chef is telling us to eat salmon."

But Jacques Torres, the New York City--based chocolatier, still eats his chocolate. Through Weight Watchers, he knocked off 20 lb. and then another 12 lb. in September in a charity competition for chefs that was sponsored by the weight-loss program. He stocks up on 70%-cocoa chocolate bars, with the goal of always having a low-sugar option on hand. Because when a craving hits, not even a Weight Watchers--trained, insanely talented pastry chef with a refined dessert palate can get in its way. "Last Sunday I was craving so much for sweets, I went to buy a cheesecake." Even worse, he confesses, "I bought it at the supermarket. I was in Jersey."

The 76-year-old designer has swatted away persistent rumours that he is set to stand down from his position as the helm of Chanel, insisting, "The world can count on me for a long time." "Retirement is not one of the topics with which I deal. Why should I?" he says. "I still have so many projects that I sometimes don't know where to begin. Chanel will still need some clothes when I'm 89."

*****

Lagerfeld, who famously shed 42kg in order to fit into the slim silhouette championed by Hedi Slimane at Dior Homme, counters that he's fighting fit. His secret to maintaining a healthy diet? Step away from the jogging pants.

"Those things are dangerous because they have an elastic band," he told Freundin, a glossy based in his native Germany. "It stretches and then you don't know when you put on weight. I hate it when you let yourself go! I'm always looking the way you see me now."

In general, the more water people drank, the more fiber and the less sugar they consumed. They also had a lower intake of calorie-dense foods -- a general marker of a healthier diet. Calorie density refers to the amount of calories in a food in relation to its weight; fruits and vegetables, for instance, tend to have a low calorie density.

While the chocolate eaters in the study had a statistically insignificant reduction in the risk of death from any cause over the eight-year span, the reduced risk for dying of heart disease was highly significant. And it was dose-dependent -- that is, the more chocolate consumed, the lower the risk for death.

Compared with people who ate none, those who had chocolate less than once a month had a 27 percent reduction in their risk for cardiac death, those who ate it up to once a week had a 44 percent reduction and those who indulged twice or more a week had a 66 percent reduced risk of dying from a subsequent heart event. The beneficial effect remained after controlling for intake of other kinds of sweets.

A co-author of the paper, Dr. Kenneth J. Mukamal, an associate professor of medicine at Harvard, said that there was considerable data from other studies suggesting that chocolate lowered blood pressure and that this might be a cause of the lower cardiac mortality found in the study. Dr. Katz, of Yale, agreed that "there are many reasonable biological mechanisms" for a protective effect from chocolate. "I like the study," he said. "It adds to the general fund of knowledge we already have."

Dr. Mukamal sounded a note of caution about the findings. "Although this is interesting and provocative, chocolate does not come without costs," he said. "For people looking for a small snack to finish a meal, this is a great choice. But it should be supplementing healthy eating and replacing less healthy snacks."

"Western diets are typically high in fat and are associated with long-term complications, such as obesity, diabetes, and heart failure, yet the short-term consequences of such diets have been given relatively little attention," said Andrew Murray, co-author of the study and currently at the University of Cambridge in the United Kingdom. "We hope that the findings of our study will help people to think seriously about reducing the fat content of their daily food intake to the immediate benefit of their general health, well-being, and alertness."

The findings are detailed in the FASEB Journal.

Rodents are thought to be good analogues to humans for studies like this, but research in humans would be needed to confirm that the effects cross over. Also, because rats live much shorter lives, study effects may play out on significantly shorter time scales than in humans.

According to Closer magazine, Lily recently turned to Kate for help on keeping the weight off. 'Kate's been telling her to try the "rock chick" diet - coffee, cigarettes, vodka and champagne, which are relatively low in calories,' a friend of the star revealed. The friends looked relaxed and happy earlier in the day as they strolled on the beach towards the yacht with Kate's daughter, Lila Grace, aged six, at times walking between them holding each of their hands.

Inspired by Betty's style (dubious though it may be), the bottle is covered in a pink leopard print layer - but the rest of the designer is up to the drinker. A selection of stickers, supplied with the bottle, let each person customize their Betty bottle in their own individual style - adding items including a butterfly-edged red hat, her iconic "B" pendant, or her famous poncho.

"I enjoy the cross branding of Patricia Field and Diet Coke," Patricia Field said. "Based on prior experience, when I designed the Diet Coke City Collection, I was energised to work on the Diet Coke Betty Bottle".

The untitled third "Bridget Jones" pic, which is still in its early stages and probably won't go into production until the end of next year, will see Zellweger reprise her role as a British publishing exec struggling to find love.

It will likely be based on the weekly columns author Helen Fielding wrote in 2005 for British newspaper the Independent in which Bridget, now in her 40s, attempts to have a baby before it's too late.

"I broke up with cheese," Vardalos recently told People. "I always say like cheese keeps calling me and trying to get me to meet at a cheap motel but I'm really committed to just staying single for awhile." Although Vardalos says that she did "like 50 other things" to lose the weight, she claims that eliminating cheese from her diet "was the thing that changed my life." Vardalos, who calls her weight loss a "crazy thing," was at the festival to screen her new movie, My Life in Ruins. The film hits theaters June 5.