If your adult weight’s always been normal, science needs you
People who’ve never been thin or fat and whose weight hasn’t changed much since the age of 18 have been invited to join Cornell University’s Global Healthy Weight Registry so scientists can tap into their habits, secrets and advice for those wishing to lose weight and keep it off
Obesity has become a massive public health issue across the world, particularly in the West: in the US, for example, more than one-third of the population is now obese and more than two-thirds overweight, while in the South Pacific archipelago American Samoa, a whopping 74.6 per cent of people are classified as obese.
With changing lifestyles, it’s safe to assume that obesity and its associated risks, including diabetes, heart disease, high blood pressure and several cancers, are coming to our part of the world, too. In China, in particular, the combination of fast-growing wealth, a culture centred on food and the one-child policy look like the ingredients for an obesity time bomb, especially as Asian people in general are particularly susceptible to type 2 diabetes.
One result of this global obesity epidemic has been the now familiar avalanche of nutritional advice, lifestyle tips and miracle quick fixes that has invaded our lives. Most methods for fighting obesity focus on persuading people to improve their lifestyles to guard against it. The advice can roughly be summed up as: eat less, eat better, exercise more.
But nutritional orthodoxy recently executed one of its periodic about-turns – essentially: sugar is now the enemy; fat isn’t as bad as we thought it was and might in fact be fine, although we’re not sure – so it’s hard to know precisely what, and most importantly whose, advice to follow when it comes to shedding those pounds or, better still, keeping them off in the first place. And given the preponderance of know-nothings, charlatans and guessers in the nutritional advice sphere, it makes sense to the one group of people who definitely know what they’re talking about: those of normal weight.
That’s the rationale behind a new initiative, the Global Healthy Weight Registry, launched by the Food and Brand Lab at Cornell University in the US. It takes an empirical, pragmatic approach to weight control, by aiming to tap into the habits, secrets and advice of people who are not only of normal weight, but have more or less always been that way.
Anyone in the world can sign up provided they have a BMI of between 18.5 and 24.9; have never seen a health care professional about their weight; and their weight hasn’t fluctuated by more than five per cent between their highest and lowest weights as an adult; exceptions are made for pregnancy. (The World Health Organisation considers anyone with a BMI of between 18.5 and 24.9 to be of healthy weight; unofficial Asian BMIs consider Asians with a BMI of 18.5 to 22.9 to be of normal weight, and Asians with a BMI of 23 to 24.9 to be overweight or “pre-obese”).
Apart from the qualifying criteria and basic demographic information, participants are asked about their eating habits, their favourite foods, their exercise habits and what they like to do in their spare time. There are also a few more tangential questions, covering subjects such as their relationship with their parents as children.
“It would be really cool, for example, if we found out that among people who have a healthy relationship with food, food wasn’t used as a reward when they were a child,” says Camille Finn, the manager of the registry.
The intention is to use those findings to produce recommendations about how to maintain a normal weight based on what real people of normal weight do, which will obviously become more statistically robust and therefore more reliable the more people sign up for the registry. The results of the first big data crunch are due in May.
The registry, which is funded by the Food and Brand Lab without any grant or external sponsorship, is modelled on the unrelated US National Weight Control Registry, run by Brown Medical School and the Miriam Hospital Weight Control and Diabetes Research Centre in the US state of Rhode Island. Studying the habits of people who have lost more than 14kg and managed to keep that weight off, it uses a similar methodology of, effectively, crowd-sourcing good advice, although it’s restricted to the United States.
“The National Weight Control Registry gave us a lot of insight into weight loss,” says Finn. “We became interested in people who had never been fat.”
Of course, those people are rather more difficult to find in the US than in, say, Hong Kong, and Hongkongers are encouraged to sign up to the registry as it seeks to broaden its base of participants. So far more than 80 per cent of those registered are in the US, but of course the secrets to maintaining a normal weight could be very different depending on location – most people in Asia, for example, don’t get fat just by responding to their environment in the way that most people in the West do – and advice is also likely to differ according to age, sex and ethnicity.
“We’re very interested in hearing unique tips and tricks from groups of people we haven’t heard from before,” says Finn. “Variations in weight are definitely to do with the environments people grow up in, their interactions with their families and so on.”
Finn adds that so far the most important factors seem to be people’s daily lifestyle habits, their environment and the people around them. The registry downplays the importance of genetics. “We want to use the results to help people, so it has to be about behaviours that people can change,” she says.
The registry is also finding that portion control might be just as important as food choices. “We’re finding that these people don’t necessarily eat healthily all day every day, but they do eat in moderation,” says Finn.
“Those strategies for staying thin can help anyone stay healthy,” says Finn. “Even if you’re not interested in being thin, there will be some very cool insights that everyone can use to strive for a healthier lifestyle.”
Wansink first founded the Food and Brand Lab at the University of Illinois in 1997 before moving it to Cornell in 2005. The lab comprises a group of academics and students covering everything from food science to agricultural economics to marketing, and its main interest is in food psychology: people’s behaviour when it comes to eating, looking at how that influences their food choices and, ultimately, their health.
“The problem we have at the Food and Brand Lab is that so many people want a quick fix – to lose weight immediately,” says Finn. “A lot of weight-loss advice is all about doing that – you’ll lose weight, but you won’t keep it off.
“Nutrition is a part of health you can control. With the registry, we’re trying to find ways we can control our environment and our own health.”