Nut and weight gain

In a study by Rogelio Almario et al. the addition of walnuts in the diet did not influence the body weight.
Despite an significant increase of 400 calories daily in a regular diet and 360 calories in a low fat diet, individuals in both groups (regular and low fat diet) did not see an increase in their body weight.

K. McManus et al. have recently published in the International Journal of Obesity a study comparing the weight loss of individuals either on moderate-fat diet and low-fat diet.
In both groups, the daily energy intake was similar but the energy from fat was different. 35 % of energy came from fat in the moderate-fat diet and 20 % only in the low-fat diet. The moderate fat diet was richer in polyunsaturated fatty acids but equal in saturated fatty acids to the low-fat diet.

People on the moderate diet were recommended to use nuts, nut butters and nut oils.
After 18 months of diet, the body weight in the moderate fat diet was more important than in the low-fat diet.

Nuts consumption, when the diet is controlled in energy, does not increase the body weight.