Are your genes to blame for your weight gain?

Are your genes to blame for your weight gain?

In a new book, weight-loss surgeon Dr Andrew Jenkinson looks at the new science of metabolism. But can we blame those unwanted pounds on our genes?

Dr Andrew Jenkinson knows first-hand that when it comes to losing weight, the oft-cited mantra “eat less, move more” isn’t as simple as it sounds. In his job as a bariatric surgeon at University College Hospital, London, Jenkinson has dealt with thousands of people who have tried everything to lose weight, but to no avail.

They come to Jenkinson seeking gastric bands or bypasses because they see no other avenue available to them. Rather than it being a failure of willpower, Jenkinson believes such people are often prey to several factors, including genetics and hormonal triggers, that drive our eating and resting behaviour. He believes there is a gap between how scientists, doctors, and dieticians understand obesity and what obese people actually experience.

“The typical story of a patient is that ‘the scales aren’t shifting’ even though they’re dieting. The doctor doesn’t believe that because he’s got them on a diet and has a more rudimentary understanding of weight regulation. He doesn’t understand their metabolism has decreased significantly,” says Jenkinson.

“The patient sees no results so they come off the diet and go back to ‘regular’ eating — and because their metabolism is so slow, their weight shoots back up, but commonly reaches a level higher than when they started the diet.”

To help close this gap in understanding, Jenkinson has written a book, Why We Eat (Too Much): The New Science of Appetite, in which he looks at the emerging evidence that everyone has their own individual weight setting — he describes it as a weight anchor.

“If someone goes on a diet, they’ll lose weight by restricting calories. But the body reacts to that by trying to keep at this weight anchor, this set point. The crux of the book is that our metabolism, the energy we use before we even move, is very dynamic and acts to protect against weight gain or weight loss. That’s quite new — most doctors don’t get that. If you’re on a 1,200-kcal-per-day diet, you’ll lose weight the first few weeks but then your body will adapt and will burn that many calories — you won’t have any more weight loss but you’ll be angry and lethargic,” says Jenkinson.

“Everyone has a weight anchor and their weight can drift up and down relative to that weight — if they’re on holidays or whatever — but we’re more or less locked into that weight. It’s like being attached to a weight by an elastic band — the further away you get the stronger the pull back to your weight setting. It’s almost counter-productive to try to consciously diet and pull away form that weight anchor. You have to concentrate on moving the actual anchor from that set point.”

Are your genes to blame for your weight gain?

Family Values

According to Jenkinson, this weight anchor or set point is mainly determined by genetics. “Some people are from bigger families than others, which you can’t change, but the book concentrates on what can be changed. Your insulin level, your cortisone level and the level of fatty acids between the omega 3 and 6 level — they’re the three things within your body which can change where your weight anchor is going to be.

“Those things are influenced by your environment — for instance, the western diet is high in sugars and carbohydrates, so your average insulin level will go up and equate to a higher weight setting. It’s nothing to do with calories — it has to do with the effect on your insulin. Similarly, if you have a massive derangement of your omega-3 and omega-6 fatty acids — which can happen from eating a lot of processed foods, fast foods, vegetable oils — then that will have a profound effect on insulin and metabolism and will force your weight up.

“The final thing is the cortisol level or the stress hormone. We know if we inject someone with cortisone or steroids they’ll put on weight, so things in the environment which can affect cortisol levels are day-to-day work and life stresses — also sedentary behaviour is terrible, not sleeping enough, not getting enough exercise, being stressed at work and home. If you’re happier you tend to be able to lose weight, while if you’re not, it’s harder to lose weight.”

Are your genes to blame for your weight gain?

Exercising the Issue

Jenkinson says exercise is also valuable in terms of weight loss, but not necessarily in terms of burning up calories.

“Exercise is very good for lowering cortisol. Now we know that if we exercise we lose weight but it’s not to do with calories but the cortisol levels.”

In the book, Jenkinson outlines steps people can take to reset their weight anchor, including cutting out sugar, reducing refined carbohydrate intake, improving their omega 3 and 6 fats ratio by eating less fast and processed food, and doing exercise that includes some muscle toning. “If you can do those things your weight anchor over time reduces and it becomes totally effortless to lose weight.

“Your weight anchor goes to a totally different setting and suddenly you’ve lost the three stone you wanted to lose. Whereas if you diet your way to that three-stone loss, you’ll put three and a half stone back on.”

Jenkinson says his book is targeted at people who have a stone or two to lose, so they can avoid getting to the point where they need surgical intervention such as a gastric band or bypass.

“I want to help people understand that low-calorie dieting is counter-productive and will increase your weight. The only solution is to change the type of food you eat and your external environment... And it should enrich your life. If you enjoy food you should get into cooking and preparing your own food, which is much better than being mindless about it.

“We’re all smoke-screened by this calorie counting… but we don’t understand we have this powerful regulator against massive weight loss or massive weight gain.”

Why We Eat (Too Much): The New Science of Appetite by Dr Andrew Jenkinson, published by Penguin Life, is out now.

Doctor's Orders

Dr Jenkinson’s tips on decreasing your average daily insulin levels:

  • Eat three meals per day
  • Have a high-fat/protein and low-carb breakfast (for example, avocado, salmon and eggs).
  • Cook/prepare your own food
  • Avoid sugar, wheat, corn, and fruit juices
  • Snack if required.

  • Have healthy snacks in the fridge: Meat, cheese, boiled eggs, yogurt, full-fat milk. Vegan options would include hummus or salsa dips, dried coconut, dark (non-sugar) chocolate. Fresh fruit is OK, but limit to two pieces a day.

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