Peanut butter provides a significant amount of protein and a number of essential nutrients, but it also contains carbs, so its use is limited in the Atkins diet. After the induction phase, when you have a greater carbohydrate allowance, including peanut butter in your diet may have some weight-loss benefits, if you eat it in moderation.
Carbohydrates on the Atkins Diet
The Atkins diet limits your carbohydrates to try to get your body to rely more on fat for energy, thus potentially increasing weight loss. The Atkins 20 plan starts off allowing only 20 grams of "net carbs" per day for the 2-week induction phase, while the Atkins 40 plan -- meant for people who have less weight to lose -- starts off with 40 grams of net carbs daily. To calculate the net carbs, subtract the grams of fiber from the total carbs.
When you're only allowed 20 grams of net carbs, you're supposed to get them mainly from nonstarchy vegetables such as lettuce, cucumber, broccoli, tomatoes and celery. After you transition to Phase 2, you add 5 grams of net carbs per week, but still you do not go higher than 60 grams per day, until you reach your weight-loss goal.
Peanut Butter on the Atkins Diet
Choose chunky peanut butter over smooth or reduced fat, as chunky contains fewer net carbs per serving. Chunky peanut butter has 7 grams of total carbs and 2.5 grams of fiber, making the net carbs 4.5 grams, but smooth peanut butter has 7 grams of total carbs and 1.5 grams of fiber, or 5.5 grams of net carbs. Reduced-fat peanut butter has more carbs: 13 grams of total carbs and 2 grams of fiber, making the net carbs 11 grams. Check the labels, as the carb content can vary by brand and type of peanut butter. Typically, natural peanut butter made with only peanuts and salt has fewer carbs than peanut butter made with added sugar.
As long as you use at least 12 grams of your available 25 grams of net carbs on nonstarchy vegetables, you can start eating peanut butter when you transition out of the induction phase of Atkins into Phase 2. Then you're allowed to use about 3 grams of net carbs per day for a serving of nuts: for example, you can have 2 tablespoons of peanut butter during this time.
Peanut Butter's Weight-Loss Benefits
Eating nuts and nut butters may actually be helpful for weight loss. People who are allowed to eat nuts while on a diet often find it easier to stick with the diet, and they lose more weight than those who aren't allowed nuts, according to a study published in The Journal of Nutrition in 2008. Possible reasons for this include: nuts are very filling; people tend to compensate for the calories they provide by eating less of other foods; and the body is unable to efficiently absorb all the calories in nuts. People don't tend to stick with low-carb diets for long, noted a study published in the International Journal of Obesity in 2004, so if you enjoy them, including peanut butter and nuts in your Atkins meal plan may help you adhere to the diet longer.
Ways to Include Peanut Butter
When adding peanut butter to your diet, measure each 2-tablespoon serving and include it only in moderation. If you're away from home and can't measure the serving carefully, it should be about the size of a golf ball. It's easy to underestimate how much peanut butter you're eating, which could cause you to go over your daily carbohydrate allowance, which would limit your weight loss. Although you can't eat a peanut butter and jelly sandwich on the Atkins diet, you can include this nutritious food in plenty of other ways. Top celery or carrot sticks with peanut butter, stir peanut butter into plain yogurt or, in the later phases of the diet, use it as a dip for dipping pear or apple slices.