The nutrients you’ll gain from peanuts are more likely to help you lose weight than to cause weight gain. In fact, people who regularly consume peanuts tend to weigh less than those who don’t eat nuts, according to a review in the September 2008 issue of the “Journal of Nutrition.” On the downside, peanuts are high in calories, so they may be responsible for extra pounds if you don't watch the amount you eat.
When you’re trying to lose weight, it’s all about the calories you consume compared to the calories you burn through daily activities. Calories are the primary reason you have to be careful about peanuts. A 1-ounce serving of dry-roasted peanuts contains 166 calories, while oil-roasted varieties have 170 calories. One ounce is only a handful of nuts, or about 28 to 32 peanuts. It's easy to eat more than one handful and rack up enough calories to gain weight.
Fats in Peanuts
One ounce of peanuts contains about 14 grams of fat, which equals 126 calories. You can fit this amount of fat into your diet, as long as your total fat intake doesn’t exceed 20 percent to 35 percent of your daily calories. The total fat consists primarily of healthy unsaturated fats. Diets high in unsaturated fats, especially monounsaturated fats, tend to induce more weight loss than diets high in saturated fats, according to a review published in April 2014 in the “European Journal of Nutrition.”
Promotion of Satiety
Rather than causing weight gain, peanuts may help you lose weight because they’re packed with two nutrients that make you feel full: protein and fiber. Fiber adds bulk, which physically promotes the feeling of fullness. Protein and soluble fiber both slow down the movement of food from your stomach, which extends satiety for a longer period of time. These nutrients also prevent spikes in blood sugar, and stabilizing blood sugar helps you maintain a healthy weight. One ounce of peanuts provides 9 percent of the daily value for fiber and 13 percent for protein, based on a 2,000-calorie-a-day diet.
Amount to Eat
Peanuts are included as one of your options for the protein food group. The “Dietary Guidelines for Americans, 2010” suggests limiting portions and replacing some of the other proteins you eat with peanuts rather than adding them to your regular diet. The U.S. Department of Agriculture recommends consuming 0.6 ounce of nuts daily, including peanuts, while the Dietary Approaches to Stop Hypertension Diet suggests eating 0.9 ounce daily. Avoid buying honey-roasted or caramel-flavored peanuts. They have about the same calories as dry-roasted peanuts, but you'll get 4 to 6 grams of added sugar in 1 ounce -- the equivalent of 1 to 1.5 teaspoons of granulated sugar -- which can contribute to weight gain.