OPINION: The truth behind healthy eating with expert Dr Giles Yeo

Family Life intern Olivia McCann spoke with obesity expert and author of Gene Eating, Dr Giles Yeo, to discover the science behind eating habits and dieting in our modern society.

We are a nation obsessed with calorie counting, Instagramming our picture-perfect food and cutting carbs to get slim. But, could our fixation on healthy eating actually be having a detrimental impact on our health? Obesity expert and leading scientist Dr Giles Yeo believes so.


Dr Giles Yeo, who has presented BBC’s Horizon and Trust Me I’m A Doctor, is a geneticist at the University of Cambridge where he studies the brain control of food intake and genetics of obesity.

In his new book, Gene Eating, Dr Yeo challenges our current approaches to dieting with scientifically-proven evidence, arguing that the perfect diet is written in our genes, meaning there is no singular diet to suit everybody.

Dissecting some of the most popular diets in our culture – including clean eating, veganism and gluten-free – Dr Yeo has scientific research looking at the impact of such diets on weight-loss.

Through his expertise, Dr Yeo advises that we need to firstly understand the truth to counting calories – that is, how our bodies will absorb different amounts of calories from particular foods. And, as Dr Yeo explains from personal experience, this is how a vegan diet can work.


As part of an experiment for BBC’s Trust Me I’m A Doctor, Dr Yeo followed a vegan diet for a month and shed 10 pounds. He also found other health benefits, such as a drop in his cholesterol by 12 per cent.

Exchanging meat for calorically less dense foods such as beans, lentils and veg – Dr Yeo found he was able to eat a lot of food in terms of kilograms, but still lose weight.

“I ate food that was really quite bulky which means it’s full of fibre, so there is more energy for your body,” Dr Yeo explains. “Is it even possible to extract all the given calories from food? No, it’s not, because you are eating things like sweetcorn and celery and in effect, I absorbed less calories and that is how I lost the weight.  You’ve got to eat a lot of lentils to match a steak.”

So, if the vegan diet is this effective (and better for the environment, too), then why don’t we all, as a nation, become vegans? Well, it’s just not that simple.

According to Dr Yeo, veganism as a dietary choice, is a first-world privilege, he says: “If you are relatively poor and underprivileged, and your parents worry about something else like working more than one job or struggle to put food on a table, are they really going to be sitting there thinking [about a vegan diet]?”



Regardless of the diet that best suits you personally, Dr Yeo believes we shouldn’t push our dietary choices onto others. The trend for promoting specific diets is largely in part due to our excessive use of social media.

For Dr Yeo, it’s not only celebrities and influencers pushing diet teas, protein shakes and hair vitamins that are causing the problem. He believes the growing trend for posting photos of our picture-perfect food is having a truly damaging effect.

“In fact, the rise of Instagram has mirrored a rise in orthorexia – a fear of eating incorrectly,” explains Dr Yeo. “It is tied up with ‘I’m only going to eat certain foods’ or  ‘I will cut out certain foods’ because ‘I want to eat correctly.’ And this is dangerous, because if you decide to be extreme about [the way you eat], it can lead to the same problems as anorexia.”

Kurbo your appetite?

So then, what does Dr Yeo think about the hotly-debated Weight Watchers app Kurbo released last month, aimed specifically at children aged eight to 17, using a traffic light system to indicate which foods children should eat compared to food products which should be limited?

Dr Yeo argues that, whilst the concept of Weight Watchers works well for adults and nationally childhood obesity is a problem, the new app is unsuitable for children.

“As an adult, you have reached your maximum growth, you are making choices, and your hormones are relatively stable,” he says. “But as a kid, you have to take a number of things into account – you have to take fluctuating hormones and the fact of increased growth.

“So, the problem with the Weight Watchers app is that it is treating kids like mini adults, and you can’t do that. We need to get kids to eat healthily and to know more about food. Which is true, we have to tackle that and we have to get kids to be healthier.”

Trying to watch our waistline in the modern world can be a huge challenge, agrees Dr Yeo, and can affect our mental health too, leading us to feel guilty that we are not eating in the correct societally perceived way.

Dr Yeo’s book is, in this way, a refreshing read as he aims to empower readers to find the diets that suit them as individuals and make their own decisions about their diet.

He emphasises: “There may well be a diet out there that suits your lifestyle if you need to lose weight, you just need to find your own strategy that suits you.”

Dr Giles Yeo’s book, Gene Eating: The Science of Obesity and the Truth about Diets, is available now in all good bookshops and on Amazon for £14.99 RRP.

Words: Olivia McCann

Family Life

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