The Healthy Food Guide team believe that making small diet and lifestyle changes brings the best long-term gains. We look at the science behind the headlines and promote a balanced way of eating.

So many diets yet so little success. HFG experts explain why fad diets always let us down

Who hasn’t fallen for a quick-fix diet that promises to get us into shape in a few weeks? As a nation, our vital statistics are worrying: 41% of men and 33% of women in the UK are overweight, while another 25% of adults are obese, so it’s no wonder many of us are desperate to find a diet that offers quick results. And there are plenty of them.

The problem is that they do seem to work initially (while we’re following them), but as soon as we stop, we pile the pounds back on again, and in some cases with more than we started with. 

‘Diets that begin with a capital D are generally a bad thing,’ says HFG expert and obesity specialist Professor David Haslam. ‘If a diet is time limited and has a start and a finish day, it will fail. If it’s just a little interlude from eating badly, the nutritional behaviours that made you fat in the first place will make you fat again. In other words, you’re only making changes for a short period of time before reverting to your old and bad eating habits.’ For this reason, David is convinced the only diets that work are those that are sustainable in the long run. ‘If you can make changes to your eating habits now and still be implementing them in 10 years, that’s a success,’ he says.

The fad diet cycle
Diets are by definition extreme, therefore hard to stick with for longer than a few weeks (think juicing, grapefruit, paleo, raw food and detox diets). We drop the pounds, but severe restrictions on our food and calorie intake aren’t sustainable, so it’s not long before we revert to eating normally and the weight piles back on. Then we go back on a diet. With each cycle, we gain more weight.

Giving up again?
‘A colleague of mine has a good expression,’ says David. ‘He says, “Anyone can stop breathing – but if you can stop breathing for 10 minutes, I’ll give you £1million.” It’s the same with not eating: eventually you’ve got to start again. The only diet that can work in the long run is one that promotes sustainable change and is linked to physical activity.’

HFG expert and GP Dawn Harper agrees. ‘Anyone can live off cabbage soup for a week or two or exclude carbohydrates for a period of time, but you fall by the wayside as soon as you try to fit in a normal working week and social engagements. “Going on a diet” means that by definition you will at some point come “off” it. I see far too many people whose weight yo-yos as a result.’

Make peace with food
‘Research shows successful weight loss is all about creating a healthy relationship with food and your body in the long term,’ says Dawn. It may not be as quick or as dramatic, but making small sustainable changes to what you eat and how active you are is a far better solution to weight management. Medical practitioners talk about the importance of a balanced diet, including the major food groups, for a good reason.

‘Those different food groups provide all the nutrients we need, and following any diet that excludes a whole group of foods for any length of time is storing up other health problems for the future,’ says Dawn. ‘Plus it’s virtually impossible to follow any such diet and enjoy a normal social life.’

Hunger leads to failure
It’s claimed that constant dieting can adversely affect our metabolism in the long run, although there’s no hard science to back that up. ‘We don’t know enough about metabolism to really know what the long-term effects are,’ says David. ‘But we do know low-calorie diets make you hungry, so that sooner or later you give in and start eating more.’

Take anxiety out of the mix
Every time you diet, then fall off the wagon, then vow to diet again, you’re entering into a war with food – and your body. If you want to break out of the cycle of constant dieting and see-sawing weight, once and for all, you’ll need a new, more straightforward attitude to food.

‘The key to losing weight is to take a more holistic approach, instead of constantly trying to diet,’ says HFG nutrition consultant Juliette Kellow. ‘This approach is more about promoting life-long healthy habits than focusing on immediate weight loss. If you can develop a healthy relationship with your body, food and exercise that doesn’t involve guilt and anxiety, you’ll be much more likely to achieve and maintain a healthy weight long term.’

A growing body of research shows this ‘non-diet’ approach works. A 2013 study tested a group of female chronic dieters: for six months, half the group were put on a traditional diet that restricted calories, together with behaviour therapy and exercise. The other half were allowed to eat normally and do exercise they enjoyed but also received social support and learned about body and self-acceptance, eating behaviours and nutrition.

Two years later, the non-dieting group had maintained their weight, were more active and had improved their cholesterol, blood pressure and self-esteem, and symptoms of depression were reduced. On the other hand, while the traditional weight loss group lost an average of 5.9kg after one year, two years later they had regained the weight and didn’t see any improvements in their cholesterol, blood pressure, levels of depression or self-esteem.

A life-long strategy

‘These results show that weight management is a strategy for life,’ says Juliette. ‘In our quick-fix society, we may yearn to drop 10lb for that holiday, wedding or special event. But it pays to understand that despite the many tempting claims made by fad diets, this approach isn’t going to give you the lasting results you crave.’

It’s also good to know this ‘non-diet’ approach has beneficial effects on our health and wellbeing — and helps us feel better about our bodies and adopt a relaxed and positive attitude towards food.

*Weight-loss results will vary and are down to your individual circumstances and the amount of weight you have to lose.