Is a low-fat diet healthy?

What is fat and why is it important?

Fat, like carbohydrates and protein, is a macronutrient needed by the body in relatively large amounts (macro) to build cell membranes, make nerve tissue and hormones, and aid the absorption of fat-soluble nutrients, including vitamins A and D.

Our bodies use fat as energy and store any excess for future use; this stored fat acts as an insulator and helps cushion vital organs, bones and other tissues, protecting them from damage. Although eating too much fat can be unhealthy, there are certain types of fat we must get from our diet because they’re essential to our health. These fats play a crucial role in the formation and maintenance of nerve tissue, including that of the brain.

What are the different types of fat?

In simple terms there are three main types of fat: saturated, monounsaturated and polyunsaturated. These all play different roles in the body.

Saturated fat is found in red meat, butter, processed meats like sausages, as well as coconut and palm oils. Too much saturated fat has been associated with cardiovascular disease, the risk of obesity and type 2 diabetes, though recent studies suggest some fats, such as those found in fermented dairy, may actually be beneficial or have a neutral effect on heart health.

Monounsaturated fat is found in olive oil, nuts and avocados, and are generally considered to be beneficial for the heart.

Polyunsaturated fats include two main types: omega-3, found in oily fish like salmon, as well as nuts like walnuts and seeds such as chia, and omega-6 fatty acids found in sunflower seeds and vegetable oils like corn oil and sesame oil. These are termed 'essential fats', as they cannot be produced by the body and must be obtained through food.

You can take a deeper dive into the different types of fats and why we need them here.

Which fats should I cut back on?

There is another type of fat, that is found naturally at very low levels in some foods such as meat and dairy but produced in larger quantities during food processing – these are trans fats. Also known as hydrogenated fats, trans fats are considered to be the worst kind of fat, and have no known health benefits. Typically, these fats are found in processed foods like pies, pastries and cakes as well as in takeaways.

Trans fats have been linked to high cholesterol and an increased risk of heart disease and cancer. Check the ingredient list on labels and try to avoid those containing ‘hydrogenated’ or ‘partially hydrogenated’ oils.

For more information on trans fats, visit the NHS website.

How much fat should I eat?

UK guidelines recommend that our total fat intake should not exceed 35 per cent of our total daily energy (calorific) needs with the maximum for saturated fats being 11 per cent. For the average, moderately active, adult female this equates to 70g of total fat and 20g of saturated fat. The UK Government also recommends that no more than 5g per day should be from trans fats.

By reducing the unhealthy trans fats in your diet and replacing some of the saturated fat with the healthier unsaturated variety, you may achieve a better balance for your heart and overall health.

Read our guide on how much fat you should eat a day.

Should you follow a low-fat diet?

In the 1990s low fat was the ‘diet du jour’, with the likes of the popular ‘hip and thigh diet’ seen as a means to successfully whittle your waist line. Low-fat eating is still used for its slimming effects, but there are other reasons why someone might follow a low-fat diet. These include as a means to manage cholesterol levels and for the management of certain health conditions such as type 2 diabetes or multiple sclerosis.

What counts as a high fat or low-fat food?

When shopping for packaged foods, look at the nutrition label and check the 'per 100g' column against the ‘high’ and ‘low’ figures below. Checking the per 100g figures is a good way to compare different brands of packaged foods:

Total Fat

High – more than 17.5g per 100g

Low – 3g or less per 100g

Saturated fat

High – more than 5g per 100g

Low – 1.5g or less per 100g

Some packaging may also show the traffic light colour coding system. This is an easy way of illustrating high or low levels with red reflecting high levels of fat and saturated fat, and green indicating low levels – aim to eat red-coded foods occasionally and green-coded foods more frequently.

Visit the NHS Choices pages for more information on food labelling.

Is a low-fat diet healthy?

A low-fat diet may be useful for some people, however, the focus should ideally be on replacing unhealthier fats with the more beneficial ones in order to ensure you are getting the fats that are essential for health and to ensure you are adequately nourished. Failure to do so may lead to dry skin, hair loss, a weakened immune system as well as the following health implications:

Vitamin deficiencies

Very low intakes of fat limit the amount of fat-soluble vitamins A, D, E and K you are able to absorb. This group of fat-soluble vitamins plays an essential role in vision, skin, immune system, hormone synthesis, bone health and the nervous and reproductive systems.

Poor brain function

Given the human brain is 60 per cent fat, the amount of fat we consume, especially the essential fatty acids, is vital for brain health and development. Studies support this by illustrating that omega-3 intake from oily fish, nuts and seeds correlates positively with memory, whilst saturated fat decreases memory and learning.

Hormonal imbalance

Women who don’t eat enough fat and have a body fat composition below optimal, may have disruptions to their menstrual cycle and potentially experience fertility issues.

Weight management issues

In the short-term limiting your intake of any of the three macronutrients is likely to lead to weight loss. While it’s true that one gram of fat is richer in calories, (providing nine kcals for every gram eaten) than the equivalent from protein or carbs (4kcal per gram), the association with eating fat and gaining weight remains less clear cut. Furthermore, numerous studies fail to support low-fat diets over other diet interventions for long-term, sustained weight control.

How can I cut back the fat in my diet?

If you’re looking to improve the balance of fat in your diet here are some practical steps to take:

• Choose more foods rich in the healthier mono- and polyunsaturated fats instead of saturated fats. In practical terms this may mean enjoying small amounts of butter and coconut oil, while focusing on olive, avocado or cold-pressed rapeseed oils.
• Choose lean cuts of meat and trim off any visible fat and remove the skin from chicken or turkey.
• Use a spray oil dispenser or measure out oil with a teaspoon instead of pouring straight from the bottle.
• Read food labels to help you make choices that are lower in total fat and saturated fat.
• Use alternative cooking methods such as baking, boiling, grilling, poaching, microwaving or steaming instead of frying or roasting so you do not need to add extra fat. An air fryer can also be helpful for minimising the use of added fats and oils.
• Cut down on processed foods such as crisps and biscuits, and avoid fried foods such as samosas, bhajis, chips and doughnuts. Replace these with healthier options like plain popcorn, nuts, seeds, pretzels and crackers.
• Make your own salad dressings using ingredients such as balsamic vinegar, yogurt, lemon juice and herbs.
• Try leaving out or using less butter and spreads when making sandwiches. Instead use nourishing foods like avocado, which is rich in monounsaturated fats.

Last words

Like many aspects of health and well-being, there is significant debate as to which is the healthiest fat to include in your diet. The evidence suggests that unsaturated fats are the most beneficial for heart health, brain function and reducing inflammation. However, a moderate amount of saturated fats may be useful too, such as that found in coconut oil and grass-fed butter. Trans fats found in processed foods, and highly refined oils are best avoided.

Following restrictive, low-fat eating plans or diets may help you lose weight in the short term, but once you go back to your old eating habits, your body will be more prone to storing fat and your weight is likely to return. If you want to lose weight, concentrate on eating a balanced diet, drinking sensibly and step up the amount of exercise you do. Be cautious of 'faddy' calorie counting and crash diets.

Interested in trying our free seven-day healthy diet plan? Click here and choose between our meat eaters, vegetarian or vegan meal plans.

Low-fat recipes

The fat contribution of most recipes can be lowered by substituting for lower fat ingredients, reducing the quantity of fat used and using lighter cooking methods such as steaming, poaching or cooking in an air fryer.

Find inspiration with these low-fat options.

Healthy low-fat salads:

Low-fat chicken caesar salad
Tuna pasta salad
Chicken satay salad

Low-fat lunches:

Indian chicken protein pots
Smoked salmon, quinoa & dill lunch pot
Vegan chickpea curry jacket potatoes

Classic recipes with lower calories:

Air fryer roast dinner
Healthy bolognese
Healthy turkey meatballs
Pasta arrabbiata with aubergine

Heart-healthy fish recipes:

Healthy fish korma
Healthy fish pie
Healthy fish & chips with tartare sauce

Discover more low-fat recipes

Enjoyed this? Now read…

Is saturated fat bad for you?
Nutritionist-approved high fat dishes that are actually good for you
7 high-fat foods to include in your diet
Eat these dietary fats to improve your skin
Understanding high cholesterol

This page was reviewed on 13 June 2025 by Kerry Torrens

A qualified nutritionist (MBANT), Kerry Torrens is a contributing author to a number of nutritional and cookery publications including Good Food magazine. Kerry is a member of the The Royal Society of Medicine, Complementary and Natural Healthcare Council (CNHC), British Association for Applied Nutrition and Nutritional Therapy (BANT).

Jo Lewin is a registered nutritionist (RNutr) with the Association for Nutrition with a specialism in public health. Follow her on Twitter @nutri_jo.

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