A review of studies confirms that nuts are not only not fattening, but in some cases help eliminate the belly.

A handful of nuts ready to be eaten.

Nuts have been benefiting humans for millennia with the vegetable proteins, vitamins and omega-3 acids that they provide, and underpinning the Mediterranean Diet with its high nutritional density. However, its consumption today is below what is desirable. This is because they are caloric foods, and many consumers limit them to sports or avoid them altogether for fear of gaining weight when they are trying to lose weight.

Any of these preconceptions, however, is wrong: nuts are not fattening, regardless of lifestyle, and can actually contribute to a weight loss diet. The key is to adapt the rations to the energy expenditure of each one, and stop considering them as snacks or snacks as usually happens in Spain, but part of the main meals of the day. To back this up with evidence, a group of researchers from universities in Spain, Brazil and Chile has reviewed more than a hundred studies and published their conclusions in the journal Nutrients.

The meta-analysis specifically included 105 randomized trials in which the effect of consuming various tree fruits and peanuts – which, remember, are actually legumes – on the parameters of overweight and obesity was verified. They were the following: body weight, Body Mass Index (BMI), waist circumference and percentage of body fat. Walnuts, almonds, hazelnuts, cashews, pistachios, Brazil nuts, macadamia nuts and pine nuts completed the catalog of analyzed nuts.

Thus, in the dietary interventions in which these foods were introduced, only one case was determined in which fortification with a dried fruit led to an increase in waist circumference: it happened with hazelnut. For the rest of the nuts, no variations in adiposity were detected compared to the participants who followed the control diet. And in a specific case, enrichment with a dried fruit led to a “significant” reduction in the belly: this is the case of almonds.

It is not a surprise: the calories in almonds have come to be defined as “negative”, in the sense that are more difficult for the body to metabolize and are stored to a lesser extent as fat, while still providing vitamins, minerals and healthy fatty acids. The authors of the present study point to a series of factors -from the fiber content to the hardness of the outer crust- that would slow down the absorption of hydrates, as long as they are consumed raw and natural.

The nutritional profile of almonds, on the other hand, may serve to explain their effectiveness in helping you lose weight, the authors add. “They have the lower lipid content of all nuts, 55%, and the cellular encapsulation of whole and raw almonds during the digestion process can limit energy bioaccessibility. In addition, fibers and polyphenols (tannins, proanthocyanins, and flavonoids) are bioactive compounds with antioxidant, antimicrobial, and antiviral properties that are prominently found in almond skin. Finally, they favor the intestinal microbiota and metabolic energy ”.

It should be emphasized that waist reduction is not a purely aesthetic matter: visceral fat, or ‘belly’, is directly related to heart risk. “We can affirm that walnuts and other nuts not only do not increase weight, but also do not negatively affect cardiometabolic markers related to adiposity,” they write. “Walnuts, pistachios or peanuts are rich sources of unsaturated fatty acids, vegetable proteins, vitamins and minerals. Health professionals should recommend them with the certainty that they will not have a negative influence ”, they conclude.