"If anybody has spent any real time listening to people's stories about weight gain and dieting, they'll know that shame is a toxic emotion that has never helped anybody lose weight in the long term. I really believe we need a deeper understanding of the reasons why people overeat and what drives their behaviour around food before we simply tell them to eat less."
His new book, Feel Great Lose Weight, which is serialised all this week in the Telegraph, sets out to unpick these complexities. He breaks things down into five sections: what, why, when, how and where we eat, how to eat well, why our emotions cause us to overeat, why timing of meals is crucial, the importance of eating mindfully, and finally, how our environment is partly to blame for rising obesity.
On that subject, early on in the book Chatterjee announces it a 'blame-free zone'. He cites an example during our interview, that's also in the book, about a female patient who came to see him who was very overweight and struggling to lose it. When her story unravelled, it transpired she had been a victim of domestic violence and after her relationship ended, she had gained a lot of weight. During therapy she admitted that she (wrongly) believed being overweight was in some way a protective measure to stop anybody from falling in love with her. Staying overweight, she reasoned, kept her 'safe'.
"You don't often read about domestic violence in a diet book, but that's why I believe this is so much more than a diet book," says Chatterjee.
"As a GP I know first hand how complicated weight can be, how far it stretches back into our childhood, how it's interwoven with other issues. You can't judge somebody for being overweight, or assume they're lazy. For somebody like my patient, it's a reaction to domestic abuse.
"For others it's less extreme. It could be that they get home from work at 8pm from a high-stress job and are too wrung out to cook, or they're lonely and eat ice-cream to find joy. For many, eating isn't so much about willpower as it is about self-worth or stress levels.
"I'm a GP and I've got the number one health podcast in the UK, but even I had a problem with sugar during lockdown because I was so stressed out. I knew it wasn't good for me. But what and why we eat often goes deeper than that. If you're stressed, hormonal changes take place in your body that cause you to crave certain foods. People aren't weak-willed; they're struggling."
Yet despite the sympathetic approach of the book, when he announced on Instagram he was writing a new book, this time about weight loss (as well as Feel Better in Five, he has also written two best-selling books on stress), he had what he calls "a bit of push back" from some of his 220,000 followers.
"They hadn't read the book because it wasn't out yet, but some of the messages I received said things like: 'I can't believe you're putting out a diet book' and 'I thought you were better than this Dr Chatterjee'. It didn't feel great if I'm honest. So I stepped back, did a bit of self-reflection, and tried to understand why they felt that way."
The answer, he thinks, is the fact terms like weight and diet have become emotive subjects in recent years. On Instagram, body positivity encourages people to love their bodies no matter their size. But Chatterjee feels this reaction misses the point of his book. "For a start, it's not a diet book, at least not in the conventional sense. There is no plan to follow. There is no talk of dropping dress sizes."
But given the link between obesity and Covid, not to mention the other illnesses that being overweight raises the risk of, from heart disease to cancer, Chatterjee thinks a conversation about weight is valid and much needed. He cites England's former chief medical officer, Professor Dame Sally Davies, who recently claimed thousands of Covid deaths could have been avoided if ministers had tackled the UK's rising obesity crisis.
"This is something we need to talk about, albeit in a kind and supportive way," says Chatterjee. "I'm a generalist – I'm a GP – so I've always taken a 360-degree approach to health. From working in a surgery, I've realised that people aren't weak-willed or greedy, but they need help to find a sustainable approach to losing weight that suits their lifestyle. That's the key. You can't tell somebody who is lonely to eat less sugar, and you can't tell somebody who works 14-hour days to spend an hour cooking every night."
On the subject of cooking, Chatterjee makes a refreshing call in his book for people to be more accepting of simple, straightforward meals rather than the elaborate and beautifully displayed ones we see on cookery shows and posted on Instagram: "Countries with the lowest obesity rates often eat bland and repetitive foods. I'm not saying you can't enjoy delicious, flavoursome foods. But neither do I think you should strive to make every meal mind-blowingly tasty. Food has become a status symbol. There's a place for that type of food, but it makes things harder because it teaches our taste buds to seek out 'blissy' foods [his term for processed, high fat, sugar and salt foods, which are irresistible to the human brain]."
And he feels that we need to change the focus when it comes to exercise. "Movement is so much more than simply burning off calories. It's a way to make you feel more alive, more energetic, to help you sleep better and strengthen your joints and muscles. There is no faster way to build up your self esteem and improve your mood than regular movement. And self esteem is one of the most important yet undervalued factors in achieving sustainable weight loss."
His book also explores how our environments have changed in the last 40 years and how that has contributed to rising obesity levels: "The Eighties changed everything in terms of food and weight, and it was when the [obesity] curve started going up. Humans didn't suddenly become lazy and gluttonous back then, but rather food manufacturers started making cheap, energy-dense processed food available wherever we looked, snacking became normal and our jobs became more sedentary.
"We didn't change, the world around us did. But don't despair, because there's plenty you can do about it."
