Tue, Jan-10-17, 02:47
Why are you fat? The new science of flab
From The Times
10 January, 2017
Why are you fat? The new science of flab
A Californian scientist who spent years struggling with her weight believes that everything we think we know is wrong
Sylvia Tara hasn’t eaten dinner for three and a half years. In fact, very little passes her lips after 3pm because she knows that managing her fat is far more complicated than the diet industry has led her to believe. For this reason, the Californian author of a new book about fat airily admits to being part of “the non-eating world”.
To many that will sound thoroughly miserable, but Tara says that she is happier than she has been in a long time. Having finally proved her life-long suspicion that her battle to stay slim “was unusually tough, always more work than it was for others”, she can confidently declare: “I control my fat, it doesn’t control me. I feel like I look good enough. I still love food, but I got control of my own fate. I won.”
Tara is not a Hollywood actress or a healthy-eating guru and she’s certainly not a fat fascist — although you will find plenty of those around hawking their books at this time of year. She is a biochemist in her late forties with a doctorate in computational chemistry and a desire to do for fat science what Oliver Sacks did for neuroscience. She hopes that her book, The Secret Life of Fat, will change perceptions of the least cherished — and least understood — part of our body.
Most of us don’t put much thought into fat except to curse it and torture ourselves about the way it sits on us, so useless and inert. However, fat is not just revolting blubber. It’s not even just an energy store. Scientists have come to believe that fat is a critical organ. It may be as important as our colon, lungs and heart. “Fat makes hormones and releases them into our system,” Tara explains. “It is a dynamic and interactive endocrine organ that has a life-or-death influence over us.”
We meet at the immaculately clean house she shares with her husband and two daughters within a large gated community in Orange County, California. This is the setting for The Real Housewives of Orange County, the stars of which have their weight carefully monitored by its producers and are booted off if they betray a hint of muffin top. Tara makes a convincing case for taking the shame out of fat. It’s not just calories in, calories out. “Metabolism is more complicated than the simple arithmetic. We have to stop the idea that obesity is just sloth and gluttony.”
Her book is the result of five years of wading through thousands of research articles and interviewing scientists at the cutting edge of fat science. It is a fascinating, disturbing and surprisingly suspenseful read. Take the case of one little girl, Layla, who had an unstoppable urge to eat. It turned out that her fat did not release leptin, the hormone that tells the brain that we don’t need more food. This was one of the first studies to show that fat can communicate with other areas of the body.
Now we know it controls our appetite, affects our emotions, supplies energy and enables the activities of other body parts. What Hippocrates termed “moistness” in the body actually exerts a powerful influence over our brain — both its size and the way it functions — as well as our immune system, our reproductive system and our bones. And since the membrane around each body cell is made of fat and cholesterol, Tara concludes that “fat holds us together”.
Yet fat will also kill us if we let it master us. America spends more on the war on fat than on the war on terrorism — $44.7 billion was budgeted for US homeland security in 2014, but about $60 billion was spent fighting fat. In the UK treating obesity-related conditions costs more than the police or fire service, according to NHS England. And fat fights back. As Tara says, it has “an uncanny, sneaky ability to control its own fate”.
For example, fat can increase our appetite if it feels threatened. Ordinarily, leptin, known as the “satiety hormone”, is our friend in the weight battle. It tells the brain when we’re full. Yet when we shed fat, it becomes more complicated. Tara says that when people lose 10 per cent of their body weight, they also lose leptin. Less fat means less leptin so their appetites “go through the roof” and their metabolism is lower.
That a dieter will become less able to control their intake and their fat cells will become more responsive to food comes as tough news for those fighting obesity. Tara describes this problem as “a killer combination”. She explains: “A person who has lost weight has to run five miles for every four miles a person who is naturally at that weight does in order to burn as many calories. If the dieter who’s achieved a new lower weight eats and exercises like a person naturally at the same weight, the dieter will put on pounds. It’s unfair.”
Still more alarming: after you lose weight, the body makes “a co-ordinated effort” to return to its known weight. “Anyone who’s reduced weight by diet or any other means tends to regain the weight with very high accuracy,” Tara says. Fat can also use our genetics against us. Certain genes have been identified that increase appetite. Bacteria can cause fat too. Depending on your microbiome (which is the genetic material of all the microbes that live on and inside our bodies), and what it’s composed of, you might be extracting a lot more calories than someone who has a different microbiome.
Fat can use stem cells to regenerate regardless of what we eat. It can even create a blood supply to promote its growth in the way tumours do, leading some obesity researchers to consider using cancer drugs to inhibit the blood vessel formation that enables fat growth. Yet what is most shocking is that fat can be enabled by common cold viruses such as adenovirus 36, the “fat virus”. One study into “infectobesity”, which followed a sample group of 1,500 air force personnel from 1995 until 2012, suggested that the ad-36 virus was prevalent in more than 20 per cent of them. Studies have shown that this virus correlates to humans having an almost four times greater risk of being overweight.
Tara admits that she is the sort of person who gains a pound if they eat a biscuit — and has to eat much less and exercise much more than her husband, an Irish-Italian who eats whatever he wants and still fits into the jeans he wore in college. Was it because she was eastern Indian, she wondered. Did it have something to do with a thrifty genotype? Was it because she was a woman? Her mother also had the same problems with weight gain and as a result would barely eat all day.
Then Tara had two children and an extra 10lb became an extra 20lb, and her weight kept creeping up. “I was trying to get my weight down and was being told I just have to eat less carbs, more paleo, exercise more, but no matter what, I would stay heavier. I got really fed up with this.” Filled with a “vengeance and fury”, Tara realised it was time to wage a very personal war. “I decided not to go on anybody else’s diet again. I had to figure out fat for myself.”
While her research has confirmed what she already knew — “we are not all created equal, at least not when it comes to fat” — she found the science that backed up her struggles was “astounding”. What’s so unfair is that we all process food differently, depending on our gender (women metabolise fat differently to men; even at birth, girl babies are heavier), genetics, race, age, hormones and bacteria.
We discuss the culture of fat-shaming and how it focuses on women — who are designed to carry more fat than men. “Donald Trump, whose medical records show he’s borderline obese, has openly ridiculed women for their weight,” Tara says. “What he doesn’t realise is that women’s subcutaneous fat is keeping them healthy. It’s a sign that their bodies are clearing fats from their blood and depositing them into fat tissue where they belong. This is much better than the sizeable visceral fat Trump carries that’s associated with risk for diabetes and heart disease.”
Tara has discovered that despite what government campaigns and fitness instructors will tell you, there is no one-size-fits-all solution to fat fighting. You need to learn how genetics, hormones, diet and exercise affect your body. However, certain strategies work across all body types. She sings the praises of vigorous exercise (such as the high-intensity interval training workouts she performs five days a week) and building muscle to increase metabolism. She also recommends seven hours of sleep to balance the hormones, drinking plenty of water and broths and eating more fibrous foods such as salads and prebiotics (found in bananas, artichokes and legumes).
Her regimen involves intermittent fasting — no food, or at least very little, between the hours of 3pm and 10am the next day. She’s at pains to stress that such an aggressive approach is not necessary for everyone, although because fasting triggers the release of fat-burning hormones, she believes it is one of the most powerful weight-loss weapons in her arsenal.
And however unfair it is that some are more prone to weight gain than others, she has little patience for those who give up the fight. “Life is not fair. Cancer is not fair, right? It’s a case of: what do you do now? Because once you’re heavy, your fat will fight back.” She tells me that her editor even managed to lose 15lb after reading her manuscript.
“What I would say to people is use whatever you can to win this battle. Whenever I have got angry about my weight, I really get on a mission. I know it’s not polite for women to say they are angry but, you know what, who cares? Use whatever emotion you have. If it’s determination, or the need for vengeance, or even if it is vanity, then don’t worry about thinking ‘this isn’t a positive trait’. Just use it.”
The skinny on fat
■ If you have excess weight, be prepared to work very hard. You will have to exhibit a high level of self-control by exercising more and eating less than a lot of the people around you if you want to make a permanent change.
■ Increase the diversity of the bacteria in your gut. Eat a lot of fibrous foods such leafy greens and prebiotics, which are found in bananas, artichokes and legumes. This will give your microbiome the tools it needs to fight fat cells. Cut down on fats and carbohydrates.
■ Fast intermittently. Your body needs a rest once in a while. In extreme circumstances, you might consider no food, or at least very little, between the hours of 3pm and 10am the next day.
■ Perform high-intensity interval training. The most effective way to reduce visceral fat is by taking up vigorous exercise for at least three days a week. Try four cycles of a 30-second all-out sprint followed by a 30-second low-intensity jog worked into a 20-minute run.
■ Build muscle. This increases your metabolism.
■ Do everything you can to maintain a healthy weight. Your fat will fight to retain its territory. Constant attacks on weight makes it stronger and more resilient so avoid yo-yo dieting.
■ Get no fewer than seven hours of sleep. This helps your hormones to rebalance and allows your satiety hormone, leptin, to replenish so you feel less hungry through the day.
■ Maintain your good habits for at least two years. Those who can keep the weight off for this long tend to conquer their fat.
■ Don’t feel guilty about weight gain. You can blame it on your genes, gender, age or the bacteria in your gut. However, you do need to get rid of it if you want to avoid an early death.
The Secret Life of Fat by Sylvia Tara (Blink Publishing)