What Is a Weight Gaining Diet?

If you have a body mass index (BMI) of 18.5 or less, you may be underweight. Low body weight can be caused by a number of factors including illness, genetics, medication, mental health conditions, or high levels of physical activity. Whether you've experienced some unexpected weight loss or your doctor is recommending that you gain weight, it may be time to make some dietary changes.

Following a weight gaining diet increases your daily calorie intake to put on more weight. The easiest way to increase calories is by eating foods that are energy-dense, which means they're high in calories. 

A weight gaining diet is not a specific plan with a catchy name or a service promoted by a certain doctor, group, or company. Instead, it is a strategy for increasing the number of calories consumed in order to add weight. It means eating more calories than you burn through exercise and daily activities. This type of diet works whether you are underweight or are specifically trying to build muscle.

What Can You Eat?

The basic premise of weight gaining diets is to consume more calories per day than you burn. Often, this requires consuming more calories than people for whom the diet is recommended are currently are eating. How people following a weight gain diet achieve this increased intake varies, but it almost always requires increasing intake of all three macronutrients: carbohydrates, protein, and healthy fats.

What You Need to Know

Some foods are better for you than others. Nutrition experts agree that the healthiest version of a weight gain diet incorporates energy- and nutrient-dense foods—meaning foods that are high in calories, but also nutritious and good for you. Foods like legumes, avocados, dried fruit, nuts, seeds, nut butter, and smoothies are just a few examples of healthy weight-gaining foods.

You could also increase your calorie intake by eating less nutritious high-calorie foods like candy, cake, chips, and sweetened soft drinks. But nutrition experts don't recommend relying on this method, because they're just not nutritious choices. Other than calories, these foods don't tend to be high in vitamins, minerals, fiber, or antioxidants.

A weight gain diet plan typically recommends at least three meals every day with larger portions if you have the appetite for it. If you don't feel like eating much, then you might do better with five or six smaller meals eaten more frequently throughout the day.

Weight gaining diets don't usually prohibit specific foods or food groups, but the healthiest versions of any diet, including weight gain diets, focus on healthy whole foods over processed foods. In the case of diets where weight gain is a goal, full-fat versions of foods like dairy products are typically encouraged over reduced-, low-, or no-fat versions.

Sample Shopping List

What you'll eat on a weight-gaining diet will vary depending on your individual needs. The following shopping list offers suggestions for getting started on a healthy and balanced weight gaining diet. Note that this is not a definitive shopping list and there may be other foods that work better for you.

• Animal protein (ground beef, sirloin steak, pork tenderloin, chicken breast and thighs, sliced turkey breast, turkey bacon)
• Fish (salmon fillets, gravlax, halibut, shrimp)
• Dark, leafy greens (kale, spinach, arugula)
• Whole fruits and vegetables (bananas, apples, mixed berries, broccoli, cauliflower, carrots, cucumbers, tomatoes)
• Legumes (black beans, lentils, soybeans, tofu, chickpeas, prepared hummus)
• Avocados
• Carbohydrates (plain bagels, pasta, white and brown rice, quinoa)
• Nuts and seeds (almonds, cashews, walnuts, flaxseeds, chia seeds)
• Nut butters (peanut butter, almond butter, sunflower seed butter)
• Full-fat dairy products (yogurt, milk, cheeses, cottage cheese, sour cream)
• Other healthy fats and oils (olive oil, unsalted butter, margarine)
• Eggs

Sample Meal Plan

Use a meal plan to prepare yourself so you have healthy, high-calorie foods on hand. This sample plan totals about 2,500 calories for one day, which should lead to weight gain for most people. It has a good balance of healthy and high-calorie foods, so you get plenty of nutrients and fiber.

If you need more calories, you can adjust this menu by adding extra snacks or eating larger portions. Note that this is not an all-inclusive meal plan and if you choose to follow a weight gaining diet, you may find that other options for meals work better for you.

Day 1

• Breakfast: 1 cup oatmeal with 1/2 cup milk and 1/2 cup raisins; 1 cup of orange juice; 1 cup black coffee
• Morning snack: 1 apple and 24 almonds; an 8-ounce glass of water
• Lunch: Sandwich with 2 large slices of whole-grain bread, 4 slices of lean turkey, 2 tomato slices, lettuce, and mustard; a 10-ounce glass of reduced-fat milk; 1 baked sweet potato with a pat of butter or margarine
• Afternoon snack: 1 protein bar; an 8-ounce glass of water
• Dinner: Fresh garden salad with 3 tablespoons salad dressing; 6-ounce salmon filet; 1 cup cooked spinach; 1/2 cup mashed potatoes with butter or margarine; 1 glass of wine (or milk or 100% fruit juice); 1 whole wheat dinner roll
• Nighttime snack: 1/2 cup plain yogurt with 1/2 cup sliced strawberries; an 8-ounce glass of water

Day 2

• Breakfast: 2-egg California summer vegetable omelet; 2 slices turkey bacon; 1 serving berry smoothie; 1 cup green tea; an 8-ounce glass of water
• Morning snack: 1 cup chopped cantaloupe; 14 whole walnuts
• Lunch: Plain bagel with 2 tablespoons full-fat cream cheese, 3 ounces of gravlax, 2 tomato slices, sliced red onion, and capers; 2 cups Mediterranean chopped salad; a cup of orange juice
• Afternoon snack: 1 slice avocado toast; an 8-ounce glass of water
• Dinner: 1 1/2 cups kale and cranberry green salad; 4 ounces grilled beef tenderloin; 1 serving sweet potato casserole; 1/2 cup lemon roasted broccoli; 1 glass of red wine (or fruit juice); an 8-ounce glass of water
• Nighttime snack: 2 pumpkin oatmeal chocolate chip cookies; an 8-ounce glass of milk

Day 3

• Breakfast: 3–4 Greek yogurt blender pancakes; 1 cup sliced strawberries; 2 breakfast sausage links; a cup of orange juice; an 8-ounce glass of water
• Morning snack: 1 banana with 2 tablespoons peanut butter; mango banana smoothie
• Lunch: 1 serving chicken Caesar salad; 1 3/4 cups red curry lentil soup with kale; an 8-ounce glass of water
• Afternoon snack: 8 hummus tuna cucumber bites; an 8-ounce glass of milk
• Dinner: 1 1/2 cups Moroccan spiced chicken and chickpea stew; 1 cup white rice; 3/4 cup roasted beet and feta salad; 1 glass of white wine (or fruit juice)
• Nighttime snack: Coconut granola served over a 1/2 cup plain yogurt; an 8-ounce glass of water

Pros and Cons

There are many benefits of weight gaining diets for those who need to put on weight for better health. Still, there are some drawbacks to these eating plans. Review the pros and cons of this diet plan to determine whether it's right for you.

Pros

Safety

If you need to gain weight, a nutritious weight gaining diet is a safe way to do it. This diet provides for added calories without artificial supplements or extra sugar, sodium, and unhealthy fats.

Flexibility

Within the parameters of nutrient-rich foods, this diet allows for plenty of free choice in what to eat. If you hate salmon, you never have to eat it. Substitute shrimp or chicken. If you dislike cooked spinach, eat it raw or try a different leafy green instead. Sweets and treats are not banned—they are just not recommended as the main strategy for increasing your calorie intake.

Sustainability

If your body continues to need the extra calories, you can keep following a weight gaining diet indefinitely. Conversely, if you reach a weight-gain goal, you can slowly cut back on calories (say, by eliminating a snack or decreasing portion sizes) in order to find the balance that works for you.

Cons

Inconvenience

This method of adding healthy calories to gain weight requires planning, shopping, and cooking. It's not as easy as simply adding a daily scoop of ice cream or bag of potato chips to your typical menu.

Battling Your Appetite

If you need to gain weight because you have a low appetite (perhaps due to a medication you are taking), it may be a challenge to eat more food. It can be very difficult to eat when you do not feel hungry.

Is a Weight Gaining Diet a Healthy Choice for You?

A weight gaining diet is very similar to a healthy weight loss diet. In both cases, most nutrition experts recommend that you eat foods that are rich in nutrients and not eliminate major food groups. You will avoid "empty calorie" foods (junk foods that contain sugar, salt, and fat, but few other nutrients). The main difference between the two diet approaches is in the number of calories you consume.

The 2020-2025 USDA Dietary Guidelines state that an individual's daily calorie allowance varies based on their current weight, age, sex, health, and activity level.

Often, a 2,000-calorie diet is used as an average. Adding about 500 calories per day to this daily level can help you gain a pound or so per week. This type of gradual change is best. Use this calculator to help you set a daily calorie goal.

Health Benefits

A weight gaining diet is energy-dense and when approached with a focus on healthy, whole foods over processed foods whenever possible, it's generally considered healthy for people who need to gain weight. People looking to gain weight may also look to over-the-counter supplements or prescription medications. But weight-gain pills are not necessarily effective or even safe, depending on your particular needs.

Health Risks

While the weight gaining diet is generally healthful and nutritious, it is not always the right course of action for everyone. A weight gain diet is it is not a good idea for anyone who needs to lose weight for health nor is it suitable for people with certain health conditions such as diabetes.

A Word From Verywell

Adding extra calories to your day by eating more nutritious foods is the best way to gain weight. Although less nutritious foods like sweets are typically high in calories, they don't have the nutritional value and health benefits offered by whole foods and don't make the best choices for a weight-gaining diet. A healthy diet is always the best way to add nutrients. Just change your calorie count to help you with your weight management goals.

Remember, following a long-term or short-term diet may not be necessary for you and many diets out there simply don’t work, especially long-term. While we do not endorse fad diet trends or unsustainable weight loss methods, we present the facts so you can make an informed decision that works best for your nutritional needs, genetic blueprint, budget, and goals.

If your goal is weight loss, remember that losing weight isn’t necessarily the same as being your healthiest self, and there are many other ways to pursue health. Exercise, sleep, and other lifestyle factors also play a major role in your overall health. The best diet is always the one that is balanced and fits your lifestyle.