Intermittent fasting for women: The truth about the trend (and why it's not your only option)

Heard of intermittent fasting and wondering whether it’s a viable option for losing weight? 

You’re absolutely right to be curious. Intermittent fasting has received a lot of attention in recent years for its supposed health benefits, from reduced risk of certain diseases to encouraging fat burning.

Despite the many health claims, intermittent fasting isn’t for everyone. Here’s what you need to know to figure out if it’s the right weight loss solution for you.

What is intermittent fasting?

Intermittent fasting is an eating pattern where you alternate between periods of eating normally and periods of eating very little or nothing at all. 

There’s no single way to approach intermittent fasting, and fasts can last anywhere from a few hours to an entire day. Some people choose to have only two meals each day, while others will only eat within a particular timeframe – say, an 8-hour window from 9am to 5pm. Others still might have set days every week when they don’t eat. 

Popular intermittent fasting methods

Given intermittent fasting’s surge in popularity, several structured approaches have emerged. The most popular methods include:

• The 5:2 diet: Involves eating as normal five days a week, then limiting yourself to 500-600 calories for two days (but not two days in a row)
• Time-restricted fasting: Requires you to eat within a particular timeframe each day and fast for the remaining hours. There are different intervals you can choose, but a common one is the 16/8 method, which involves eating normally within an 8-hour window and fasting for 16 hours
• Eat Stop Eat: Consists of one or two 24-hour fasts each week
• Alternate-day fasting: Switch between non-fasting days and days of very low or no calories
• The Warrior Diet: Small snacks, usually fresh fruit and veg, during the day and a large meal at night
• One meal a day: Fast for 23 hours and eat a big meal within a 1-hour window each day

How intermittent fasting impacts the body

The point of intermittent fasting is to help your body burn fat. When you eat normally – that is, three meals a day and maybe snacks – the calories from your food are your body’s primary energy source. Your body then turns to its own sugar stores (glycogen) as an energy source. But when you’ve gone an extended period without food, these sugar stores get used up, and your body turns to fat instead.

Other things happen, too. Your insulin level drops, and your human growth hormone (HGH) level increases to further encourage body fat burning. Your body also kick-starts its cellular repair process, whereby it removes damaged cells and regenerates new ones. Lastly, you go through changes to different genes and cellular pathways, which promote longevity and protect against disease.

This is why intermittent fasting is said to have a number of health benefits beyond weight loss. 

Benefits of intermittent fasting

Some of the claimed benefits of fasting include:

• Weight loss: Fasting encourages your body to use fat as a fuel source, plus it generally means consuming fewer calories
• Lower inflammation: It may decrease inflammation markers in the body, which are linked to many chronic diseases [1]
• Improved insulin sensitivity: Intermittent fasting may help improve insulin resistance and blood sugar control [2]
• Lower blood pressure: Fasting may improve vascular function, which can reduce hypertension [3]
• Better cognitive function: Fasting may support concentration, memory and brain health [4]
• More energy and improved physical performance: Many advocates report increased energy levels and better endurance
• Improved gut health: Fasting may promote the growth of beneficial gut bacteria that contribute to a healthier gut [5]
• Cellular repair (and, as a result, potential cancer protection): Fasting activates cellular repair, which may reduce cancer risk [6]

What the science says (and what’s still unclear)

Several studies back up the benefits mentioned above, especially when it comes to weight loss. For instance, a 2025 study – the biggest systematic review on intermittent fasting, which analysed 99 clinical trials – found that intermittent fasting could be just as effective for weight loss as classic calorie-controlled diets, and alternate-day fasting in particular was more effective [7].

That being said, a lot of research has come from animal or cell studies, with limited results from human subjects. These kinds of studies can be helpful, but they don’t always translate to real-world human outcomes. Research on intermittent fasting is also still in its early days, with the long-term effects of this eating pattern still relatively unclear. 

Some research has also come out refuting many of the claimed health benefits, pointing out that intermittent fasting is beneficial when it comes to weight loss, but no better than other diets when improving overall health [8].

And there’s even some evidence that intermittent fasting can increase your risk of cardiovascular death by 91%, contradicting a lot of the research that has come out about intermittent fasting’s heart-health benefits [9].

Why intermittent fasting is different for men and women

Another thing to note is that intermittent fasting can have different effects on men and women, and it’s all to do with hormones.

Many experts suggest that intermittent fasting can be risky for women because it affects sex hormones like progesterone and estrogen, the two mainly involved in the menstrual cycle [10]. Throughout your cycle, these hormones fluctuate as a result of gonadotropin-releasing hormone (GnRH), which is highly sensitive to things like stress and calorie intake.

When your body thinks you’re in a state of starvation, it reacts by suppressing the production of certain hormones, potentially leading to menstrual cycle changes, low libido, sleep problems, hair loss, headaches and even infertility.

For this reason, intermittent fasting isn’t recommended if you’re trying to conceive, pregnant or breastfeeding. Health experts also suggest doing lower-intensity fasts like the 5:2 diet to minimise the potentially negative effects.

Is it just another fad?

Intermittent fasting has attracted a lot of attention in recent years. From documentaries and celeb endorsements to viral posts all over your social media feeds, it suddenly feels as if intermittent fasting and all its promises are everywhere. It’s become popular because it’s perceived as not only a weight loss tool but a game-changer for your overall health.

However, diet trends come and go, and an intermittent fasting diet is possibly no different. The last several decades have seen all kinds of diets crop up, including the Atkins diet, paleo, keto, zone diet, the cabbage soup diet, the lemonade diet, and the list goes on. Many of these have fallen out of favour or retreated from the spotlight, be it due to their genuine health risks or simply because something else has come along and taken centre stage.

That’s not to say that intermittent fasting will fade, too – but it is important to remember that diet trends are changing all the time, and even though the bandwagon is tempting, it’s not necessarily worth jumping on.

Potential risks

For many people, intermittent fasting is quite safe. But if you’re new to it, you might be better off starting with a gentler option, such as time-restricted eating or the 5:2 diet

Intermittent fasting is also generally not recommended for children and teenagers, people with diabetes, or people with certain medical conditions. If you’ve got a history of eating disorders or food anxiety, you’re also best approaching intermittent fasting with caution. Eating on such a restricted schedule can exacerbate existing issues.

Other possible risks to be aware of include:

• Fatigue and reduced energy
• Dizziness
• Headache
• Constipation and other digestive issues
• Nutritional deficiencies
• Low blood sugar
• Mood swings or poorer mental health
• Sleep problems
• Potential for overeating during eating periods

If you notice any of these warning signs, it’s an indication that intermittent fasting isn’t working for your body.

Always chat to your GP before undertaking a new eating plan, especially if you’ve got one of the risk factors mentioned above.

Nutrition should be personal

One of the most crucial things to remember is that nutrition and dieting aren’t one-size-fits-all. What works for one person may not work for another, and a single diet can have vastly different results. Your body is unique and influenced by a range of factors, like hormones, metabolism, genes and lifestyle, meaning generic diets may not meet your needs.

Tuning into how your body responds to different foods and eating patterns, and learning to recognise your own hunger, energy and mood cues, are key to finding an approach that truly works for you. This may be some version of intermittent fasting, and it may not – it’s about recognising that your body is highly individual.

Juniper supports a holistic approach to weight loss

Instead of looking to trends, Juniper endorses a more holistic and sustainable approach to weight loss. If intermittent fasting doesn’t suit your needs, our programme may be a better fit. 

With the Juniper Programme, you can access weight loss medication tailored to your health and goals — never one-size-fits-all. Our app helps you track progress, connect with your care team, adjust medication as needed, and access expert support. You'll also get structured tools to build lasting habits and ongoing care.

Kickstart your weight loss journey with Wegovy, a groundbreaking weight loss injection that mimics the GLP-1 hormone to help control cravings, delay stomach emptying, and keep you feeling fuller for longer.

We help you make lifestyle and habit changes, and we’re in it with you for the long run, having helped thousands of women achieve their weight loss goals.

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