Nuts are high in calories — so why are they a go-to diet snack?

Nuts are a staple diet snack — yet they are far from low in calories. Nutritionists point to two key reasons they can still support weight management: they help maintain a sense of fullness, and they promote a metabolic environment favorable to weight loss.

Among the most popular varieties in Korea are almonds, pistachios — demand for which has surged on the back of the Dubai chocolate trend — and peanuts, which have recently drawn attention as an ingredient in diet-friendly peanut butter.

Based on the recommended daily serving of one handful, or about 28 grams, the calorie counts are notable: almonds come in at 166 kilocalories, pistachios at 163 and peanuts at 158. While those figures are relatively high, even that small handful is enough to keep hunger in check.

Nutritionists say almonds, pistachios and peanuts are low in carbohydrates but rich in nutrients that promote satiety — a well-balanced combination of protein, unsaturated fat and dietary fiber. A single 28-gram serving of pistachios, for example, contains 6 grams of protein, 11 grams of unsaturated fat and 3 grams of fiber. Together, these components slow digestion, sustaining energy levels longer and curbing appetite. They also help stabilize blood sugar and lower the risk of metabolic syndrome, ultimately helping put the body in a state more conducive to losing weight.

Medical experts note that when blood sugar spikes sharply after a meal, the body releases large amounts of insulin. The hormone lowers blood sugar but at the same time triggers the storage of excess glucose as fat. A rapid rise in blood sugar also intensifies appetite.

A study published in PLoS ONE in 2014 involving 803 adults found that more frequent consumption of nuts such as almonds and pistachios was associated with lower risks of metabolic syndrome and obesity. The researchers said nuts' ability to support blood sugar regulation may have contributed to the reduced risk of metabolic syndrome. Improved blood sugar levels, they noted, can have a positive effect on body weight, abdominal obesity and metabolic syndrome.

Almonds have been the subject of the most weight-loss research among nuts. A paper published in Cell Metabolism in 2011 had 65 overweight or obese adults eat 28 grams of almonds five days a week for three months; by the end, participants showed improvements in body weight, triglyceride levels and waist circumference compared with before the study.

Peanuts, meanwhile, have been studied for their potential to help prevent obesity when eaten alongside high-fat meals. A paper from Pennsylvania State University published in The Journal of Nutrition in 2017 found that participants who drank a peanut shake after a high-fat meal had blood triglyceride levels 32 percent lower than a control group that consumed a different shake of equivalent calories.

Nuts remain one of the most research-backed options for a weight-conscious snack, offering a rare combination of caloric density and metabolic benefit in a single handful.