Low-fat eating

What low-fat means

There is no single definition. The WHO advises adults to keep total fat to 30% of calories or less, with no more than 10% from saturated fat and 1% from trans fat. On 2,000 kcal a day, 30% is about 67 g of fat. On UK labels, “low fat” means 3 g or less per 100 g, and “reduced fat” only means at least 30% less than a similar product.

What the evidence shows

A Cochrane review of 37 trials in 57,079 adults who were not trying to lose weight found that eating a smaller share of calories from fat led to slightly lower body weight, by about 1.4 kg, with no sign of harm to blood lipids or blood pressure.

For deliberate weight loss, low-fat has no special advantage. A 2015 meta-analysis of 53 trials found that low-fat diets did no better over a year or more than higher-fat diets delivered with the same intensity, and slightly worse than low-carbohydrate diets, by about 1.2 kg. Calories and whether you can keep to the diet decide the result.

Which fat matters

The type of fat matters more than the total. The NHS advises no more than 30 g of saturated fat a day for men and 20 g for women, and says there is good evidence that swapping some saturated fat for unsaturated fat lowers cholesterol. Fat is also needed: it supplies essential fatty acids and helps you absorb vitamins A, D and E.

In practice that means trimming butter, fatty meat, pastry and cream before olive oil, nuts, seeds and oily fish. Use the fat filter in the recipe search to set a ceiling per meal. Our recipes show total fat only, so check the saturated fat on packaged ingredients yourself.

Common questions

Sources

1. World Health Organization (2023): WHO updates guidelines on fats and carbohydrates
2. NHS: Facts about fat
3. Cochrane (2020): Effect of cutting down the fat we eat on body weight
4. Tobias et al., The Lancet Diabetes & Endocrinology (2015): Low-fat diet interventions versus other diet interventions on long-term weight change, systematic review and meta-analysis