What is the 5:2 vegetarian diet?

As you might expect the 5:2 vegetarian diet follows the same principles as the original 5:2 diet while abstaining from meat, fish and poultry.


Now in its 10th year, the 5:2 diet first hit our screens in August 2012 when the BBC broadcast an episode of Horizon called 'Eat Fast and Live Longer'. Doctor and journalist Michael Mosley presented the diet as ‘genuinely revolutionary,’ and as a result, published The Fast Diet book in January 2013.

Visit our ‘All you need to know about diets’ page for recipes and more expert advice on weight loss, including low-GI and the Mediterranean diet’.

What does the 5:2 diet involve?

Followers of the 5:2 diet eat normally for five days of the week, during this time there is no restriction on calories or food groups; on the remaining two days calorie intake is limited to just a quarter of your recommended daily intake – that’s 500 calories for women and 600 calories for men. How you choose to consume these calories is entirely up to you – you may prefer three small meals spread through the day or one single meal, at a time best suited to your lifestyle.

This method of intermittent fasting offers plenty of flexibility – you can choose your fasting days and fit them around your lifestyle and commitments; there is no restriction on what you eat as long as you keep to the calorie restriction on fast days.

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Is the 5:2 vegetarian diet healthy?

Although there are a limited number of studies assessing the specific benefits of the 5:2 diet, those looking at intermittent fasting and other alternate day eating plans show promise.

From the evidence to date it would appear that for those at a healthy, normal weight as well as overweight or obese adults, methods of intermittent fasting are unlikely to be harmful to health. In addition to this, it may be argued that the 5:2 vegetarian diet offers the benefits for weight management of a plant-based diet combined with the potential health gains achieved through the practice of fasting.

Intermittent fasting is hot news in the diet world with possible health benefits, beyond those of weight loss, ranging from improved digestion and brain function to a reduced risk of some chronic illnesses such as heart disease and cancer. One of explanations for this is that periods of time without food, which can be as short as a prolonged overnight fast, initiates a process in the body called autophagy. Best thought of as the body’s housekeeping process, autophagy sweeps away dead cells and pathogens and promotes tissue repair.

A carefully planned, vegetarian diet which supplies all the essential nutrients you need for your age, gender and activity levels may indeed be a healthy way to eat, with fewer reported cases of obesity, heart disease and type 2 diabetes than that of meat eaters. There may also be a lower overall risk of cancer and even more so for those who adopt a vegan diet.

However, if you do choose to follow the 5:2 vegetarian diet, make sure your non-fast days are packed with nutritious options, including vegetables and fruit, beans and pulses, nuts, seeds as well as wholegrains. On fasting days be sure to include protein sources, such as eggs, tofu and beans, with some carbs to help manage and control your appetite. Avoid fasting on two consecutive days – instead break your week up by, for example, fasting on Monday and Thursday – this helps prevent tiredness.

It is worth remembering that restricting food intake does not suit everyone and some studies report a small number of dieters experience negative effects, such as feeling cold, irritable, low in energy or hungry.

Vegetarian chilli

Is the 5:2 vegetarian diet effective for weight loss?

The 5:2 vegetarian diet does appear to be an effective weight loss plan, however, there is little evidence to suggest it is any better for either weight loss or blood sugar control than that of other calorie-controlled diets.

That said, one of the diet’s main advantages is that many 5:2 followers find it easier to stick to because it allows you to eat normally for five days of the week, making compliance relatively high.

Is the 5:2 vegetarian diet safe for everyone?

As with all diets, pregnant and breastfeeding women as well as diabetics on medication, should seek medical advice before embarking on a restricted eating programme. Furthermore, this sort of diet may be unsafe for teenagers and children, who may miss out on crucial nutrients needed for growth and be at risk of developing unhealthy eating habits.

If you are frail or elderly, have a physically demanding job, are a keen exerciser, suffer migraines or have a blood sugar management issue, this way of eating may not be appropriate for you.

Please note, if you are considering adopting any form of restrictive eating or diet, please consult your GP or a registered dietician to ensure you can do so without risk to health.

More information...

If you're going to give it a go, make sure you include our 5:2 recipes – they are low in calories and nutrient dense.

Weight loss and good health can be achieved by following a healthy, balanced diet. Find your perfect portion size, guideline daily amounts and nutritionally balanced breakfasts, lunches, dinners and snacks:

How to eat a balanced diet
A balanced diet for vegetarians
A balanced diet for vegans

Want facts and information on other diets? Read more about other popular weight loss plans:

Ketogenic diets
The dopamine diet
More popular diets

This article was published on 11 February 2022.

Kerry Torrens is a registered nutritionist (MBANT) with a post-graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.


All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.

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