This is a level 3 recipe (weight maintenance and active lifestyles). Fruits and low-fat dairy milk are low calorie foods I’d generally recommend for weight loss. This strawberry banana smoothie for weight gain has peanut butter added for higher calories and fat.Keep in mind that this smoothie recipe is intended for a snack, not a complete meal. You can substitute the peanut butter for other nut and seed butters (almond butter, sunbutter, etc.). The calories per serving will not change much with this modification.To make this smoothie even higher in calories, you can use whole milk. To make a lower-calorie smoothie, substitute skim milk for the 2%. Unsweetened soy milk is another way to cut calories (depending on the brand). You could also experiment with using defatted peanut flour in place of the peanut butter. Peanut flour provides yummy peanut flavor to recipes for far fewer calories than peanut butter. You may need to adjust the amount of peanut flour used in the recipe, however. It doesn’t tend to work as a 1:1 substitution for peanut butter.We’re using whole fruits here, not fruit juice, to make the smoothie thick and add fiber. Though high fat foods and highly processed carbs can help promote quick weight gain, it’s still important to maintain a balanced diet. This means including sources of fiber and protein, like you’re getting in this healthy smoothie.Nutrition information is for one serving of the recipe.