How to lose weight and keep it off – according to science

Towards a Healthy Mind & Body

calorie intake

You may have tried losing weight in the past.  If so,  the chances are that you experienced some challenges sticking to your diet.

That’s because sticking to a strict calorie controlled diet is not an easy task in modern environments where tasty and high energy foods are attractive and easily available.  For example, a main course meal at a restaurant is likely to contain more than half of the calories required for an entire day.

Dieting is also made particularly difficult by our body’s rapid response to decreases in food intake but opposing lack of response to overeating. This will be a familiar experience for many who have experienced almost immediate increases in hunger when dieting.


Overeating not detected

Recent research has shown that overeating is poorly detected in humans, even when energy intake is increased to provide an excess of more than 1,000 calories per day.  In this study, overeating with 150% of the required daily calories did not change the appetite of participants.

The findings showed how the body fails to adjust to account for these additional calories.

This makes sense from an evolutionary perspective because in environments with limited access to food, overeating when food was available to our ancestors would increase their chances of survival by keeping them fuelled until food was available again.

This shows that being aware of calorie intakes is important because short periods of accidental overeating can be sufficient to cause weight gain or impair weight loss. For example, evidence suggests that increases in body weight during the festive period are maintained throughout the rest of the year.

Such periodic bouts of over-eating may also be responsible for incremental annual increases in body weight. Similarly, overeating on a weekend can easily cancel out a strict diet that is maintained on weekdays.

But understanding how easy it is to overeat does not mean that weight loss can’t be achieved. In fact, knowing this can help with weight loss – by being more aware of dietary choices.


Don’t forget exercise

Despite our body’s bias for weight gain, correct diet and lifestyle changes will produce and maintain weight loss if this is the desired aim.

Exercise may often be overlooked as people seek “the best diet for weight loss”. But getting active still remains important if you want to lose weight, especially for maintaining weight loss over prolonged periods of time.

Exercise can complement dietary changes and help to minimise the increases in hunger experienced from dieting alone. This is because exercise does not cause an increase in hunger to the same extent as dieting, despite also creating an energy deficit for weight loss.

In fact, hunger is reduced when exercising intensely, which may help to stave off hunger pangs while increasing the energy deficit.

The importance of exercise for maintaining weight loss was also recently highlighted with participants from the TV weight loss competition The Biggest Loser.

When participants were monitored for six years after the show it was revealed that the people who maintained their weight loss had increased their physical activity by 160%.

In contrast, those who had regained their lost weight had only increased their physical activity by 34%.


Flexibility is needed

Regardless of which dieting approach you choose, it is likely you will need a degree of flexibility – as most diets will require some compromise.

Lets say, for example, you are invited to attend a special occasion that will likely involve eating more than you would normally.

Being aware that your body is not likely to respond to the increased calorie intake means that you can adjust your behaviour to avoid or compensate for any overeating.  For example, you could do so by being more mindful of food choices in the days before or after an occasion, or increasing your exercise levels to counter any excesses.

What all this shows is that ultimately we should not rely on feedback signals from our body to detect levels of calorie intakes. Instead, conscious monitoring of diet and lifestyle behaviour is required.

The good news is that, for most people, this will counter a body’s natural bias for weight gain.  Appreciating this need for conscious monitoring will help you to achieve your desired weight loss goals.The Conversation

By Kevin Deighton, Reader in Nutrition and Metabolism, Leeds Beckett University

This article is republished from The Conversation under a Creative Commons license.



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