Ever wondered why, no matter how hard you pound it at the gym or measure portions in the kitchen, you can’t shift those last few kilograms? We have some surprising answers – and excellent tips to get you to your goal.
When it comes to the eternal question, “Why are we fatter now?” the medical community has long pointed a latex-gloved finger at the “big two”: too much food combined with not enough exercise. But new research suggests there’s a whole host of other fat-promoting factors that have nothing to do with how many kilojoules you cram in or how often you work up a sweat. “When looking for ways to combat obesity, we need to be aware of all the possible causes,” says Dr Yann Klimentidis, a geneticist at the Nutrition Obesity Research Centre in the US. Here, we give you the seven major fat traps standing between you and your goal weight.
1. Check The Heat
A warm home could be bad news for a hot body. A study in the International Journal Of Obesity found people with higher than average home temperatures were more likely to become obese. It’s to do with your body’s brown fat, which, unlike white fat, burns kilojoules. Brown fat is switched on and off during the day, depending on the temperature and whether you’re exercising or eating.
When the mercury drops below 18°C, it starts burning energy – excess kilojoules that might otherwise have been stored as fat – to keep you warm. If you don’t regularly expose yourself to temperatures lower than 18°C, you start to lose your brown fat, along with its slimming powers.
As temps fall from 28°C to 15°C, we steadily burn more energy, explains Dr Fiona Johnson, a health psychology researcher at University College London who specialises in eating behaviour and weight regulation. “So turning up the aircon by any amount is likely to have some small effect.” Keeping your home and office below 18°C – and as close to 15°C as you can tolerate – works best. Brrr.
2. The Bacteria In Your Gut
It sounds a bit Mulder and Scully, but 90 percent of the cells in your body aren’t human; they’re microbes that can have a big impact on your weight. When a team of US researchers took bacteria from the guts of thin and obese humans and transplanted them into mice, the ones that got the bacteria from the obese people put on more weight.
Turns out some common gut bacteria can suppress a protein called FIAF (fasting-induced adipose factor), which stops the body from storing fat. And – you guessed it – a diet high in fat and sugar encourages the growth of these bacteria. Cutting down could not only help you lose fat, but also create a gut environment with more beneficial bacteria.
If you don’t fancy giving up glazed doughnuts, Japanese research showed overweight people who kept their unhealthy diet but had a probiotic every day lost an average of one kilogram in 12 weeks. Not bad for doing virtually nothing. Oh, and avoid antibiotics unless strictly needed, as even low doses alter the balance of tummy bacteria in ways that could increase fat. See, it does pay to listen to your gut.
3. The Air You Breathe
You’re all set for a run. But will it be the treadmill or the street? If you live in a busy city, the treadmill might be better, because breathing in polluted air boosts both the size and number of fat cells, according to US research. They say raised levels of TNF-alpha – tumour necrosis factor-alpha, a protein involved in inflammation – may be to blame.
“We believe air pollution plays a very important role in the current obesity epidemic, especially taking into account exposure over a lifetime and outdoor activity,” says study leader Dr Xiaohua Xu. Even in the countryside you can’t entirely escape it, as pollution particles are carried on the wind. Try Mapmyrun.com – it’s a cute little community site that can help you find and examine other runners’ routes that are least traffic-clogged. Breathe easy.
4. Post-Pub Carb Attacks
That late-night kebab carries a bigger fat-boosting punch than it would in the middle of the day, because kilojoules are used differently depending on when they’re eaten. Our bodies have evolved to store fat from food eaten at night, rather than burn it.
Tests on mice suggest restricting your meals to within eight hours of waking could be beneficial (so if your alarm goes off at 7am, you’d have your last meal at 3pm). In the study rodents on a high-fat diet that were allowed to eat only within an eight-hour period every day ended up weighing 28 percent less than those who ate the same number of kilojoules whenever they wanted.
“Our findings suggest regular eating times and ‘fasting’ for a significant number of hours a day might be beneficial to health,” says lead researcher Dr Satchidananda Panda. To be fair, we’ve always known a 2am petrol-station pie dash is a bad idea.
5. The Daily Commute
You step onto a busy bus and someone sneezes in your face. Bad luck: you’ve just caught obesity. Ridiculous? The idea is controversial, yes, but there’s growing evidence to back it up. Through Dr Nikhil Dhurandhar’s US research, he found that one in three obese people tested positive for past infection with cold virus adenovirus-36 (AD-36), compared with just 11 percent of slim people. And the obese subjects who tested positive were fatter than those who didn’t.
Another study reported children who tested positive for past infection with AD-36 weighed on average 23kg more than kids who tested negative. For now, normal hygiene measures are the best way to reduce your risk of infection, says Dhurandhar. But he and others are also working on a vaccine for AD-36. Watch this sneeze.
6. Your Mom’s Cravings
If your mother indulged in Colonel Sanders – KFC, not the man – while pregnant, you’re going to have to work harder to stay slim. Weirdly, the opposite is also true: pregnant women on low-carb diets are more likely to have children who grow up to be obese, according to UK research.
Turns out too many carbs, as well as too few, interfere with the normal settings of genes involved in metabolism. There’s even evidence that these changes can be transferred down the generations, so even your grandmother’s pregnancy diet could influence your weight.
If you’re pregnant, or planning a pregnancy, be aware that your diet could have a lifelong impact on your child’s risk of being fat. There’s no better incentive to eat a clean and balanced diet!
7. The Wrapper On Your Food
Sure, you check the nutritional labels on your grub, but what about the packaging itself? Some common plastics and tin linings contain endocrine disrupters – chemicals that can interfere with your metabolism-regulating hormones. In a study, Dr Elizabeth Hatch found that fatter men have more traces of a group of endocrine disrupters known as phthalates in their blood. It’s early days for the research, she says, and many scientists still argue the levels of these chemicals in food packaging are too small to cause any health problems.
But since Hatch says the most common sources of endocrine disrupters are “food and food-contact materials: bisphenol A [BPA] in tinned foods, phthalates in certain plastics and pesticides in fatty foods”, it’s a good idea to avoid PVC packaging. Luckily, BPA-free food storage containers are now widely available in supermarkets and some countries have even banned BPA from baby bottles and other children’s products. But virtually all tins used for foods like baked beans and soup contain small amounts of BPA, as does the plastic packaging generally used for microwave meals. Lower your risk by sticking to organic, unpackaged foods like meat from a butcher and loose veggies.
Check out these 10 metabolism boosters, ranked according to effectiveness! Also, whether you’re serious about shedding those last few kilos or you’re just starting out, sign up for the Women’s Health 12-week Lean Body Blitz programme today.