6 Secrets of Weight-loss Science
SOMETIMES IT SEEMS STAYING TRIM ISN’T A FAIR FIGHT. WHILE SOME SHED POUNDS WITH APPARENT EASE, FOR OTHERS THE SCALES WON’T BUDGE. TO FIND OUT WHY – AND WHAT YOU CAN DO ABOUT IT – RW CHECKED INTO THE WORLD’S LEADING OBESITY RESEARCH LAB
Are you a grazer? A craver? We can help
very week over the past few months, a new volunteer has checked into the metabolic ward of the Pennington Biomedical Research Center in Louisiana, US. Each stays for 24 days; she or he is fed meals that are meticulously measured so their calorie intake is less than what their body burns, guaranteeing weight loss. Participants begin the study by spending three days in a metabolic chamber. Dr Eric Ravussin, lab-coated concierge of these suites, compares them to ‘hotel rooms, but with a glass wall and precise sensors’. Here, every inhalation and exhalation is measured to assess each volunteer’s metabolic rate (the number of calories burned by their bodies). Then, they spend 17 days on a campus, where their meals and exercise are recorded, before returning to the chamber for evaluation. The aim is to measure their weight loss and how their metabolic rates are affected by the process of cutting calories.
As many of us know, if losing weight is hard, keeping it off can be harder. Ravussin made headlines with a study revealing that extreme diets can cause a significant metabolic slowdown: in other words, to stay the same weight, a person who dropped from 110kg to 90kg would have to eat far less than someone who has always weighed 90kg. ‘It’s as though people who lose weight are almost doomed to regain it,’ says Ravussin.
There’s an old Indian parable in which blind men attempting to describe an elephant arrive at different conclusions, depending on
Ewhether they’re holding the trunk, tusk or tail. Likewise, obesity is difficult to conceptualise fully. It results from a multitude of disparate, yet coexisting, issues – from metabolic factors and emotional problems to a lack of exercise and poor nutrition. Too often, these issues are studied in isolation. At Pennington, however, the researchers are attempting to look at the whole elephant.
In its Ingestive Behavior, Weight Management and Health Promotion Laboratory, Dr Corby Martin analyses feeding studies investigating everything from how the pace of eating affects how full we feel, to how group dynamics – the influence of your friends – influence your food choices. In another lab, Dr Owen Carmichael uses functional magnetic resonance imaging (FMRI) to better understand food cravings at a neurological level.
But how does all this apply to you? Pennington’s collective expertise helps to identify seven ‘fat types’ – seven different ways in which your body and brain conspire to pack on the kilos. You may be predominantly one type or, more likely, a combination of several types. Even the skinnier among us will see something of themselves here, and understanding the inner workings of our relationship with fat is a powerful weapon in the battle to stay lean for good.