King's College London

However, scientists from the Department of Nutritional Sciences at King’s College London have found that actually around 20% of the fat from nuts is not absorbed and therefore neither is 25% of the calories, which are excreted.

Looking at almonds in particular, the team found that eating nuts also resulted in a lower and slower release of fat into the bloodstream, which is beneficial for a whole range of health problems such as obesity, cardiovascular disease, type 2 diabetes. It has also been shown that those who regularly consume nuts tend to have smaller waists and better gut health.

In addition, scientists have found that the waste that enters the large intestine from the unabsorbed nuts, provides good fibre and source of nutrients for our gut microbes. Further research is underway to determine whether regular consumption of nuts can have a specific benefit on the good gut microbes, which have been linked with overall health and happiness.

Dr Sarah Berry from the Department of Nutritional Sciences at King’s said: “Our research shows how important it is to look past food labels on some foods, since what is displayed in terms of fat and calorie content may not accurately reflect what actually happens once consumed.

"Nuts are a great example of this and it is crucial we move away from the long-held belief that they are full of calories and make us gain weight. Indeed, we have shown these to be a great snack choice, holding numerous benefits for our gut and cardiovascular health.”

Dr Megan Rossi added: “Enjoying a diverse range of nuts, particular unroasted with the skin on, is likely to be best for our gut microbes. In terms of portion, a small handful (30g) is a good guide. At the end of the day, remember food is meant to be enjoyed, the fact that nuts also have a health benefit, is really just an added bonus.”