Almonds and other nuts are high in calories— or are they? A new United States Department of Agriculture (USDA) study in the American Journal of Clinical Nutrition found that almonds actually supply about 25 percent fewer calories than nutrition labels indicate—130 per ounce rather than the 170 calories listed on packages. Typically, food companies calculate calories using a standard formula but this method apparently overestimates calories in nuts, in particular.
In the study, people ate three different “almond” diets for 18 days each: One included 1½ ounces of almonds a day, another 3 ounces; the third diet had no almonds. During each phase, the researchers analyzed stool samples to see how much of the food was not being digested. It turned out that a fair amount of the fat, carbohydrates and protein in almonds passed through the intestines undigested— and thus not all their energy (calories) was absorbed. These findings help explain why studies have found that nut eaters tend not to gain weight (and often even lose weight) when nuts are eaten in place of carbohydrate-rich foods.
The study was supported by the Almond Board of California. Other nuts, as well as peanuts (technically legumes), probably have similar effects, at least to some extent, the researchers say, casting doubt on the accuracy of all nut labels. Another USDA study earlier this year found that pistachios have 5 percent fewer calories than the amount typically stated on labels.
There’s reason to think that calorie counts listed on slivered or chopped nuts and nut butters are more accurate than those for whole nuts. That’s because the smaller the particles, the greater their digestibility and thus the more calories (and nutrients) you absorb. A study a few years ago even found that the more that people chewed their almonds, the less fat they excreted (meaning more fat was absorbed).
Even at only 130 calories an ounce—which is just a small handful—almonds and other nuts are still calorie-dense foods that you should eat in moderation.