So if intermittent fasting doesn’t work for weight loss then what does?

The concept of intermittent fasting exploded in popularity in 2013 courtesy of Michael Mosley’s 5:2 diet, with people swearing by this method for weight loss and further health perks.

But new research published in the Cochrane Library has cast doubt on its efficacy, concluding that “compared to regular dietary advice, intermittent fasting may result in little to no difference in weight loss or quality of life”. It even went so far as to suggest it was only marginally better than doing nothing at all.

How can this be? The theory, relating to weight loss, is that intermittent fasting was only ever a Trojan horse for eating fewer calories – the common denominator behind dropping fat. By limiting your opportunities to eat throughout the week, most people will automatically eat less. But there are many ways to achieve this, and nutrition experts say intermittent fasting may not be the best fit for you.

What is intermittent fasting?

Intermittent fasting involves scheduled periods of fasting and eating. There are three prevalent formats:

Why is intermittent fasting ‘only slightly better than doing nothing’?

A 2026 article in the British Medical Journal described intermittent fasting as “no better than conventional dieting” and “only slightly better than doing nothing”. Damning words, it would seem, on a protocol employed by millions over the last decade.

“Any reduction in calories can lead to weight loss,” registered dietitian and University of Lancashire lecturer Vassiliki Sinopoulou tells me. “This is no different to any other diet.”

“Everybody wants to find that one thing that is going to be the answer to everything,” adds Heart Research UK nutritionist Amie Leckie. “But when it comes to diet, it’s just a case of eating well. For weight loss, we have to consider overall calorie consumption, not just the fact you’re fasting.”

For example, if someone is doing alternate-day fasting but they eat excessive amounts on their non-fasting days, they may still gain weight because they are consuming more calories than they are expending overall. The fact they are fasting does not change this.

That doesn’t mean intermittent fasting is redundant. Instead, Sinopolou says, the linchpin to a successful weight loss diet is finding one that works with your lifestyle.

“The way to lose weight is to reduce your calorie intake compared to your needs,” she says. “Anything that leads you there in a safe, sustainable way that you can follow for life is going to be the best thing for you.

“If intermittent fasting fits your way of life and your routine, it can work. Some people prefer to eat lots of smaller meals, other people prefer eating fewer larger ones.”

That means no crash diets or eight-week summer body plans – just maintainable eating behaviours that nourish the body as needed while containing an appropriate number of calories for your lifestyle and goals.

Read more: I specialise in coaching people aged 40-plus – do these six things for immediate results

Why weight-loss jabs are not the solution

Sinopoulou’s sustainable approach is also the reason why she is not a fan of weight-loss drugs becoming mainstream.

“These drugs can lead to weight loss without you trying to push yourself to do it, because you naturally don’t feel hungry,” she says. “But, as is the case with a lot of dieting, when it’s seen as a short-term change, you go back to your old habits and you gain the weight back – maybe even more, some studies show.”

Weight-loss drugs make sense for combatting health conditions in high-risk populations. But for those now using them for primarily aesthetic reasons, Sinopoulou suggests trying to lose weight “within a sustainable, healthy diet that will last for life”.

Read more: Expert warns why this daily habit is shortening your life – even if you exercise

open image in gallery

The merits of intermittent fasting

The latest intermittent fasting review focuses largely on weight loss, which it says “remains the primary strategy for reducing health risks and societal consequences associated with overweight and obesity”. But there may be benefits to intermittent fasting that extend beyond this one marker.

“There is research to suggest fasting can lead to improvements in cholesterol levels, improvements in blood pressure and lower inflammation in general, which is a risk factor for cardiovascular disease,” says Leckie.

“Digestion also takes a lot of energy. Many people eat all day long without realising, and I think a lot of that comes down to people not balancing their meals properly – they’re not eating enough protein or fibre, so they feel hungry an hour after a meal.

“When we do intermittent fasting, we give the body a break. We give it time to work on things at a cellular level and repair, so we do see certain benefits from that such as reducing CRP (C-reactive protein) levels, which are a marker of inflammation, and cognitive benefits as well.”

However, Leckie adds, she doesn’t believe there is any magic dietary formula that delivers superior benefits. It is the principles of eating balanced meals and giving your body a break every once in a while that offer the best results.

“Personally, I don’t do intermittent fasting,” she says. “But I make sure my evening meal is substantial enough and has the right mix of protein, fibre, fats and carbohydrates so I don’t feel hungry, then I don’t eat again until the next morning. It’s going back to basics.”

This aligns with a previous discussion I had with Dr Valter Longo – the man who inspired much of Dr Michael Mosley’s 5:2 diet. He pointed to research which found that 16- to 24-hour fasts can temporarily increase cholesterol levels, potentially increasing cardiovascular disease risk.

For this reason, he prefers 12-hour eating windows for managing weight and improving heart health, as these complement the body’s natural day-night rhythm. They are also far easier to stick to when you are asleep for more than half of your fasting time.

Read more: Four things you can do to reduce inflammation and cut heart disease risk, according to the experts

open image in gallery

Three easy rules for a healthy diet

1. Keep it simple

Most nutrition experts suggest a simple approach: they want you to do the basics, do them well and do them daily.

“A healthy diet has to be rich in fruits and vegetables, and it needs to have a caloric intake that’s suitable for your ideal weight,” says Sinopolou.

Dr Longo highlights recent research from the Karolinska Institutet in Sweden. It found that nutrition is one of the biggest levers we can pull to protect our health, and a plant-heavy diet containing plenty of vegetables, fruits, legumes, nuts and whole grains is associated with slower ageing, better brain health and fewer chronic diseases.

2. Prioritise protein and fibre

Prioritising protein and fibre can help you feel fuller for longer, Leckie adds. These nutrients also support bodily processes such as maintaining tissue strength, balancing blood sugar for sustained energy levels and improving gut health.

Protein can be found in meat, dairy products, beans, lentils, tofu and tempeh, while fibre is present in most plants. Build your snacks and meals around these foods, she advises, then add carbohydrates later – preferably in the form of whole grains.

“With fibre, variety is key,” Leckie says. “Ideally, you want to be getting 30 different types of plants into your diet each week.”

3. Cook from scratch

Sinopolou and Leckie agree on this final point: people should cook from scratch as often as possible.

“We know that ultra-processed foods are wreaking havoc on our health, and luckily that is something that is being spoken about more now,” says Leckie. “My rule of thumb, and Heart Research UK’s stance on diet, is if you couldn’t make it in your kitchen, don’t eat it.”

Read more: What foods nutrition experts really eat to stop chronic illness in old age (and always avoid)

open image in gallery

An easy way to immediately improve your diet

Sinopoulou has a simple piece of advice for managing weight and diet.

“Listen to your psychological hunger cues, as this is something a lot of people have lost touch with nowadays and they cannot differentiate between cravings – which come from reward signals in your brain – and hunger.”

This disconnect may have been elevated by the rise of ultra-processed foods that are designed to be moreish, calorific and high in sugar, salt and fat, she adds.

“They’re delicious, and all you need to do is open your cupboard door and they’re ready to eat,” Sinopoulou says. “It’s probably better to avoid having them at home if you cannot control your urges around them, which is how most people feel around these foods.”

Weight loss jabs can make us more cognisant of the difference between hunger and cravings, she says. But without them, we can still be more mindful of why we’re gravitating to the fridge or cupboard, taking a moment before opening the door to determine whether hunger or craving is driving our behaviour.

“If you hear your stomach gurgling, that’s definitely a physiological hunger cue,” Sinopoulou says. “If you see an advert on the TV for chocolate, and you know you have some in the cupboard, you might think, ‘Oh, that would be nice.’ That’s probably more of a craving.”

Eating a balanced diet can aid this process, helping you feel more in tune with your body.

“I think if people focus on protein and fibre, a lot of the food noise disappears because they are satiated, they have energy and they’re not getting those blood sugar dips that leave us reaching for the biscuit tin,” says Leckie.

So there you have it. In our search for a shiny new magic diet formula for better health, we’ve ended up back at the start, with simple (if unsexy) diet advice that has stood the test of time:

If you can find a way to do these few things, in a format that works for your lifestyle, you’re probably on the right track.

Read more: I’m a personal trainer – this is what I’d tell a client who wants to lose belly fat