Psst, want to know the secret to losing weight?

WHEN the Prime Minister was struck down by Covid, he blamed the severity of his illness on being ‘too fat’ — and there have since been lots of photos of him running with his personal trainer. Unconfirmed rumours suggest that he has also been practising intermittent fasting.

If you want to lose weight, combining dieting with exercising is key. Countless studies have shown that, although exercise is great for toning your body and improving mood, by itself it’s not a particularly effective way to lose weight.

This was strikingly demonstrated in recent research from Kentucky University involving healthy but sedentary and overweight volunteers. Half started exercising twice a week for at least 90 minutes a time or until they’d burned about 750 calories per session (burning an extra 1,500 calories a week). The others exercised six times a week for about an hour a day (to burn an extra 3,000 calories a week). They all also kept food diaries. After three months their measurements were checked and compared.

It must have been disappointing, because those who had been doing three hours’ exercise every week had lost, on average, around 1½ lb of body fat; the more vigorous exercisers lost just under 4 lb of fat. That compares with 18 lb of fat you could expect to lose in that time doing my Fast 800 programme, where you cut back to 800-1,000 calories a day. When the researchers looked at the food diaries, they discovered that the volunteers had, on average, unconsciously increased their calorie intake by around 1,000 calories a week. The moral of this story is that exercise is wonderful but you can’t expect to lose weight if you go for a 20-minute walk, burn 50 calories, then scoff biscuits when you get home. Two chocolate biscuits? Around 180 calories.