The science of weight loss - and putting it into practice

I recently completed a free online module by the University of Newcastle called the science of weight loss to be more informed when talking to patients and also to shift my own Covid kilos. One of the myths around dieting is that your metabolism slows down in middle age.

  Actually, we now know that your metabolism stays stable between the ages of 20 and 60, even during major hormonal shifts such as pregnancy and menopause. According to The Guardian, a woman of 50 will burn calories just as effectively as a woman of 20.

  The data comes from a major study by Herman Pontzer, an associate professor of evolutionary anthropology at Duke University. The study looked at more than 6,400 individuals – from eight days to 95 years old – and found that exercise regimes and diet are unlikely to boost your metabolism because the human body is programmed to keep its average daily energy expenditure within a defined range. Your metabolism only starts to slow down in your 60s and continues until death.

  “I think there is a deep evolutionary reason to this,” says Pontzer. “In the industrialised world, burning more energy than you eat would be great, but in the wild, that’s a bad strategy. The reason we’re gaining weight is not only because there’s more food available than we have evolved to expect, but because they’re modern, industrialised foods, designed to be overeaten. So you’ve got this perfect storm for making people obese.”
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  There are also lifestyle reasons for the middle-age spread. Those in the 40s are more likely to be caregivers of elderly parents and/or young children, as well as be in the middle of their careers and have more work responsibilities. The combination of stress, a sedentary lifestyle, being time-poor and sleep deprived, plus the availability of convenience food products and food delivery apps means we are consuming more calories than we intend.

  I found for me personally keeping a food diary was the most effective way to monitor what I was eating and why. I realised I was snacking more out of boredom, or because other people were snacking, than actual hunger.

​  The Japanese have a word for this: Kuchisabishii - eating because your mouth is lonely. Having to write down what I ate for 4 days kept me accountable, even if no-one was going to read my food diary.

​  One other thing I learnt is there is no one single diet that is best for weight loss. The best diet is the one that you can stick with long term without feeling miserable. If you are aiming to lose weight successfully or want to be more mindful about eating, here are some tips.

• A realistic goal is to only try to lose 5% of your body weight.
• Find out about portion sizes and keep a food diary.
• Use a smaller dinner plate so your plate looks fuller.
• Wait 10 minutes or have a glass of water before going back for seconds.
• Understanding the reasons why you want to lose weight. Is it for physical comfort, to get to a lower clothes size or because of other people’s comments? Change for yourself will be more sustainable than changing to please someone else.
• Exercise may not help you lose weight, but it helps improve how your body does background tasks like reducing inflammation, balancing the levels of stress hormone and decreasing your risks of heart disease and diabetes.

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