The obesity surgeon’s guide to weight loss
Shedding pounds can still be delicious, Dr Andrew Jenkinson tells Fiona MacRae. If you follow the science
You overindulged at Christmas but you’re counting calories now and getting back into exercise, so all is well, right? It seems not. Counting calories may work in the short term but eventually you’ll put all the weight you lost back on and more. Exercise, meanwhile, won’t do much for your waistline unless you can fit in between five and seven hours a week. Do the recommended 150 minutes a week and you can expect to lose just 4˝lb — and that’s after a year.
So says Dr Andrew Jenkinson, a consultant bariatric surgeon at University College London Hospital who is on the front line of the obesity epidemic. “In January, when you are trying to lose weight, it’s all about the type of food you eat and how that affects your body, rather than how many calories you are expending or how much you are eating,” he says.
In Jenkinson’s new book, How to Eat (and Still Lose Weight), he explains how some of our favourite foods play havoc with hormones involved in regulating appetite and metabolism. Some of his advice to get these hormones back on track will be familiar (avoid processed food; leafy green vegetables are good for you). Other tips (a glass of fruit juice is worse than a glass of Coke; throw away your vegetable oils — “they are not food”) less so.
If you understand how the food you eat affects your body and your brain, you’ll find that you naturally want to eat healthier food, Jenkinson says. As a result you won’t just lose weight, you’ll keep it off — and with little or no willpower.
It is quite a promise, but Jenkinson should know: he has carried out studies on the role of appetite hormones and devoured others’ research. He has also listened to his patients: over the past 20 years he has carried out about 5,000 sleeve gastrectomies — weight-loss operations in which most of the stomach is removed. “I was really stimulated by the science of why someone chooses to have such a drastic operation,” he says. “Why does someone want me to remove three quarters of their stomach rather than go to the gym or go on a diet? I learnt from my patients that maybe it wasn’t that simple.”
Think hormones, not calories
It’s not calories that are making us fat, Jenkinson says, but something called leptin resistance. The hormone leptin is the “master controller” of weight. It tells the brain how much fat you have stored. If you’ve put on weight, your brain will “sense the leptin level in the blood and respond by increasing feelings of fullness and decrease your appetite. You naturally eat less and you seamlessly lose the weight you’d gained, until your leptin level returns to normal.”
Eat the wrong foods, however, and levels of another hormone, insulin, rise, throwing a spanner in the works. Large amounts of insulin prevent the brain from gauging leptin levels. Thinking they are low, it tells you to eat more. “Insulin is increased by consuming too much sugar, too many foods containing refined carbohydrates such as wheat and too much vegetable oil,” Jenkinson says. “These foods do not cause weight gain because they contain too many calories, but because of the confusion they cause to your normal weight-control signalling.”
The wrong kind of food
The food Jenkinson is referring to includes cakes, chocolate, sweet drinks, pasta, bread and polyunsaturated vegetable oils such as sunflower, canola and rapeseed oil. He advises cooking in butter or olive oil when frying and counsels against processed food.
It may surprise you to learn that fruit juice can be worse than a glass of Coke. Fruit juice contains a lot of the sugar fructose, which is more harmful than the sucrose (which is half fructose, half glucose) found in many fizzy drinks. According to Jenkinson, fructose drains the cells that process it of their energy stores. This sends a starvation signal to the brain, which leads to an increase in appetite and weight gain. (If you’re not watching your weight, then fruit juice is OK.)
Why our body stores fat
We all have a “weight set-point” — the weight your brain wants you to be. If you do lose weight, your brain will fight to get the weight back up, Jenkinson says. Your metabolism will slow and your appetite will increase. You may even end up heavier than before, thanks to your brain instructing your body to store extra fat as an insurance policy against future food shortages (otherwise known as diets).
Your weight set-point is largely determined by your genes. But stress and lack of sleep can push it up, Jenkinson says, as can a western diet full of sugar, refined carbs, fructose and vegetable oil. A better diet — leafy greens and colourful vegetables, fish (not farmed), red meat (beef and pork), pulses, beans and berries — can lower your set-point and help keep any weight you lose off. Buckwheat and quinoa are good alternatives to traditional carbs.
How to “surf” a craving
All food triggers the release of the feelgood brain chemical dopamine, but food high in sugar and fat sparks particularly high amounts. When the brain is reminded of these foods, by adverts for example, we crave the pleasure they give us and eventually feast on them habitually, without thinking.
Habits can be changed, says Jenkinson. It takes 66 days, on average, to form a new one and 30 to 60 days for the temptation to perform a bad habit to wane. Cravings can be overcome by “surfing” them — riding them out until they fade away. “Concentrate on your breathing and be mindful of how the craving feels,” he says. “Observe the intensity of the craving as it gets bigger, like a wave, until it peaks and then crashes.”
What about Jenkinson’s own bad habits? He says he eats fast food occasionally (he last had a McDonald’s about three months ago) “but then it takes me six months before I can do it again.”
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