New Research Casts a Damning Light On Intermittent Fasting for Women - But What Do Experts Reckon?

If wellness trends had a hall of fame, intermittent fasting would probably be in it.

Over the past decade, the idea that when you eat could be just as important as what you eat has become one of the most widely adopted approaches to weight loss. For years, nutritionists have sworn by it, celebrities have credited it for their physiques, and social media is flooded with fitness influencers promoting their fasting windows.

The premise is simple enough: restrict eating to certain hours of the day or alternate between days of eating and fasting. The most popular formats include the 16:8 method (fast for 16 hours, eat within an eight-hour window), the 5:2 approach (eat normally five days a week and restrict calories on two), and alternate-day fasting.

Intermittent fasting has been framed as something of a metabolic shortcut - a way to encourage fat burning, improve blood sugar control and support weight loss without the need for traditional dieting.

But a new review published by the Cochrane Library is throwing a bit of cold water on that narrative. After analysing more than 20 clinical trials involving nearly 2,000 participants, researchers found intermittent fasting did not lead to significantly greater weight loss than standard dietary advice.

In other words, while it may help some people lose weight, it’s not necessarily more effective than more traditional ways of eating.

So is intermittent fasting still worth trying, or has the hype simply outpaced the science? To unpack what the research really means (and whether the approach still has a place in a healthy lifestyle), we asked several experts to weigh in.

While you’re here, you might be interested in the benefits of mindful eating or our guides to intuitive eating. Recipe hunting? Scroll for expert-approved healthy breakfast ideas, healthy snack ideas, healthy smoothie recipes, plus what to eat after a workout, here.

Trying to lose weight? What nutritional experts really want you to know before you try intermittent fasting.

What is intermittent fasting?

Intermittent fasting isn’t technically a nutritional diet; it’s an eating pattern. Instead of focusing on specific foods or calorie counting, the approach centres on restricting the hours you eat.

The most common methods include:

• 16:8 fasting: eating within an eight-hour window and fasting for the remaining 16 hours
• 5:2 fasting: eating normally five days a week and restricting calories on two days.
• Alternate-day fasting: rotating between normal eating days and fasting or very low-calorie days.

The theory behind fasting is that longer gaps between meals allow the body to switch from burning glucose to burning stored fat. This metabolic shift is sometimes referred to as “metabolic switching”.

But in reality, many experts say the benefits often come down to something far simpler: people end up eating fewer calories overall.

“My initial reaction to the new review is that it’s actually very consistent with what many of us see in clinical practice,” says Dr Deepali Misra-Sharp, NHS GP and menopause specialist.

“Intermittent fasting has often been promoted as though it has a unique metabolic advantage, but when researchers compare it with more traditional approaches to weight loss, the results tend to be very similar.”

What does the current science say?

The overall finding from the latest research was fairly clear: intermittent fasting didn’t produce meaningfully greater weight loss than other structured eating plans. That doesn’t mean it doesn’t work - just that it’s not necessarily superior to other approaches.

“Most studies show intermittent fasting works primarily because it reduces overall calorie intake, rather than because fasting itself triggers a special fat-burning state,” says Dr Misra-Sharp.

She points out that research generally shows weight loss of around 3–8% of body weight over several months, which is broadly comparable to what’s seen with standard calorie-restricted diets.

For pharmacists and healthcare professionals working with patients day to day, these findings reflect what they already see in practice. “From a clinical perspective, the findings are not entirely surprising,” explains Hira Malik, co-founder and pharmacist at Oushk Pharmacy.

“Many of the benefits associated with intermittent fasting often come from a reduction in overall calorie intake rather than the timing of meals itself. When calorie intake is similar, intermittent fasting and more traditional dietary approaches tend to produce comparable weight-loss results.”

She adds that the findings reinforce an important reality in nutrition science. “There is rarely a single dietary strategy that works for everyone. Sustainable weight management is usually the result of consistent lifestyle habits that individuals can maintain long term, rather than short-term or restrictive approaches.”

Some studies have explored other potential benefits, including improvements in blood sugar control, insulin sensitivity and blood pressure. Research published in the New England Journal of Medicine has also suggested fasting may trigger cellular repair processes linked to ageing and metabolic health.

But there’s still a big caveat: many fasting studies are short-term, often lasting just eight to twelve weeks, meaning we still have limited data on how well these approaches work over the years.

What experts want you to know about intermittent fasting

Despite the mixed evidence, many nutrition professionals say intermittent fasting can still work for some people, but not necessarily for the reasons social media suggests.

“Intermittent fasting can work for some people, but it’s not a magic bullet, and it’s often oversimplified,” says Henri Davy, registered nutritional therapist. “In practice, I often see people focusing on when they eat while forgetting that what they eat still matters far more for energy, metabolism and long-term health.”

According to Davy, the improvements many people experience often come down to better overall eating habits. “Many of the benefits associated with fasting actually come from improved blood sugar regulation and eating fewer ultra-processed foods,” she explains. “For many people, a simple twelve to fourteen-hour overnight fast can support metabolic health without the stress of extreme fasting protocols.”

Malik agrees that intermittent fasting may still be helpful for some individuals - particularly when it simply provides structure to eating patterns. “Intermittent fasting may work well for people who find that limiting their eating window helps reduce mindless snacking or late-night eating,” she says. “For people who prefer fewer meals during the day, it can provide a structure that makes it easier to control overall intake.

Some specialists are also concerned about the way restrictive eating trends can spread online. “Arbitrary food rules can create a toxic relationship with food,” says Dr Nirusha Kumaran, GP and women’s longevity specialist.

“For younger people especially, these rules can become internalised and evolve into more serious disordered eating behaviours.” She adds that framing restrictive eating patterns as “wellness” can make unhealthy habits harder to recognise.

“Real balance includes flexibility, enjoyment and satisfaction from food - not rigid limits or shame-based eating.”

So, what’s the verdict on intermittent fasting?

If the latest research tells us anything, it’s that intermittent fasting isn’t a miracle weight-loss solution, but it’s not completely useless either.

For some people, restricting eating windows may naturally reduce late-night snacking or mindless grazing. But for many others, the approach simply isn’t practical - or necessary.

Ultimately, experts say long-term health tends to come down to consistent, sustainable habits rather than specific eating schedules. “My preference when supporting patients with weight management is a balanced dietary pattern that focuses on overall food quality,” says Dr Misra-Sharp.

One of the most consistently supported approaches in research is the Mediterranean-style diet, which emphasises vegetables, fruit, whole grains, legumes, olive oil, nuts and lean proteins.

Rather than focusing on rigid fasting rules, experts recommend prioritising:

• Protein and fibre at meals
• Minimally processed foods
• Regular eating patterns that support energy and appetite
• Habits that are realistic in everyday life.

Because ultimately, the best way of eating isn’t the trendiest one - it’s the one that helps you feel nourished, energised and able to live your life well.

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