Surprisingly, one new study has reached the conclusion that being fat is good for you. But can it be true?
It's the first week of January, when many men wake up after a two-week orgy of over-consumption and start planning exercise regimes and Atkins-style fad diets.
But hang on a sec: new research suggests that maybe we shouldn't bother. That's not because exercise regimes that kick in during the coldest months of the year are prone to failure, or that men are notoriously poor at sticking to diets.
No, it's because being overweight might be good for us.
Yep, you heard that right. According to a large new study, carrying a few extra pounds can actually reduce the risk of premature death.
Can it be right? We weigh the evidence.
Fat can be healthy?
The new research seems to go against everything doctors have been telling us for years. Can being fat really be healthy?
The first thing to say is that this was no Mickey Mouse study. Dr Katherine Flegal, who carried out the research, is a distinguished epidemiologist from the National Center for Health Statistics at the Centers for Disease Control and Prevention in the US.
Her previous research on the subject came to similar conclusions, and her latest study involved analysing over 100 data sets from around the world involving, in total, around three million people.
In other words, her results cannot be lightly dismissed. And what she found was that people who were modestly overweight (with a BMI above 25 but below 30) have a 6% lower rate of premature death from all causes than people of healthy weight. Even the mildly obese had no extra risk of premature death.
"People are sometimes amazed that overweight people have a lower mortality than normal-weight people, but a lot of the research has shown this for a long time," said Dr Flegal.
The benefits of being overweight
The fact is that nobody knows why carrying a few extra pounds might reduce your chances of premature death, but experts have a few theories.
It could be that, in critical situations, and especially in older people, fat may have a protective effect. Dr Flegal suggests that, "if you are sick, there is a lot of extra demands and stress on your body with tests and treatments, and maybe if you have a little extra weight, you are better able to deal with these."
Other experts have suggested that it may be that doctors are more likely to take health complaints in overweight people more seriously, subconsciously viewing normal weight people as more healthy.
And then there's the possibility that some component of fat tissue is actually healthy, though Dr Flegal admits nobody knows what that might be.
What many experts are starting to believe is that the distribution of fat across the body is more telling for health than simple BMI measures. For example, fat around the stomach is thought to be less healthy than fat around the hips.
Taken together with the new research, all this suggests that fat and weight may be more complex issues than anyone previously thought.
Should you try to lose weight?
So should you bother starting a new year diet? If you're seriously overweight, the answer is a resounding 'yes'. Even the latest research shows that obese people have the greatest risk of premature death.
For mildly overweight people, the answer now seems more complex. But what shouldn't be forgotten is that many other good studies have shown that even carrying a few excess extra pounds can be unhealthy.
For example, a recent Swedish study found that overweight men had a significantly higher risk of heart disease than normal weight men, which lead the report's author Dr Johan Arnlov, to suggest that even the mildly overweight may still need to lose weight for the good of their health.
Others argue that the new study looks at risk of death, not risk of disease. It could be that overweight people lead slightly longer lives on average than normal, perhaps because of more thorough medical interventions, but that their lives are also more likely to be blighted by ill health.
Fit and fat?
But some experts also believe that it's not how fat you are that's most important (as long as you're not obese), but how fit you are.
Professor Steven Blair is an expert on weight and health from the University of South Carolina. He agrees that overweight people are less healthy than their normal weight peers, if they're unfit. What his research has shown, however, is that, if they're fit, "the harmful effect of fat just disappears."
In other words, if you're a little overweight but exercise regularly, you may be a lot healthier than a slimmer friend who never gets off the couch.
But other experts sound a note of caution. The problem with being a bit overweight is that it's all too easy to slide into further weight gain. So whatever your size, the first thing to ensure is that your weight is stable. It's possible that you can be fat (though never obese) and fit, if you're not piling on pounds.
To diet or not to diet?
So it could be that losing the Christmas padding is not the most important thing you can do for your health this month. The latest study has certainly muddied the waters on whether the mildly overweight among us need to spend January feeling guilty about failing to stick to our diets.
But in another way the advice hasn't changed at all. If you're very overweight, you need to slim down. If you're carrying a few pounds too many, you just need to exercise and eat well, regardless of what it does to your weight. Losing the pounds may not be so important, but living healthily most definitely is.