What to eat when it's hard to gain weight?

November 16, 2025 •

3 min read

According to the World Health Organization, being underweight can contribute to a range of health issues, including a weakened immune system and nutrient deficiencies. This guide offers practical and healthy advice on what to eat when it's hard to gain weight, focusing on nutrient-dense options rather than empty calories.

Quick Summary

This article outlines a healthy eating strategy for individuals who find it difficult to gain weight, such as those with a fast metabolism. It focuses on incorporating calorie-dense yet nutritious foods into frequent meals and snacks, including homemade smoothies, whole grains, and healthy fats, complemented by strength training to build muscle mass.

Key Points

Increase Calorie Intake Safely: To gain weight, consume more calories than you burn, focusing on nutrient-dense, not junk, food.
Choose Calorie-Dense Foods: Incorporate healthy fats from avocados, nuts, and olive oil to boost caloric intake efficiently.
Prioritize Quality Protein: Eat lean meats, fatty fish, eggs, and full-fat dairy to help build muscle mass rather than just fat.
Embrace Complex Carbohydrates: Use starchy vegetables like potatoes and whole grains such as rice and quinoa for sustained energy.
Strategize Snacks and Fluids: Combat a small appetite by eating smaller, more frequent meals and drinking high-calorie beverages like homemade smoothies between meals.
Pair Diet with Strength Training: Combine a calorie-surplus diet with resistance exercise to build muscle effectively and ensure healthy weight gain.
Be Consistent and Patient: Healthy weight gain takes time. Stick to your plan and track your progress patiently for sustainable results.
Use Healthy Toppings and Add-ins: Add cheese, nuts, seeds, and healthy oils to meals to increase calories without significantly increasing portion sizes.

For some, gaining weight can be a significant challenge, often due to a fast metabolism, genetics, or a smaller appetite. The key to healthy weight gain is not simply eating more, but rather eating more of the right foods—specifically, calorie-dense and nutrient-rich options. A sustainable strategy involves creating a consistent calorie surplus, ensuring you consume more energy than you burn daily, combined with strength training to promote muscle growth instead of just fat.

Prioritizing Calorie-Dense Foods

To increase your daily caloric intake without feeling overly full, focus on foods that pack a lot of energy into a smaller volume. Healthy choices are critical to avoid health problems associated with excessive intake of junk food.

Nuts and Nut Butters: Almonds, walnuts, and peanuts are rich in healthy fats and protein. Two tablespoons of peanut butter alone can add nearly 200 calories to your day.
Healthy Fats and Oils: Adding extra virgin olive oil, avocado oil, or coconut oil to cooking, dressings, or smoothies is a simple way to boost calories. A single tablespoon can add around 120 calories.
Dried Fruits: Concentrated versions of their fresh counterparts, dried fruits like raisins, dates, and apricots offer a quick calorie and antioxidant boost.
Full-Fat Dairy: Whole milk, full-fat Greek yogurt, and cheese are excellent sources of calories, protein, and calcium. Use them in smoothies, as a topping, or on their own.
Avocados: High in monounsaturated fats and fiber, a single avocado can add over 300 calories to a meal.

Building Meals Around Protein and Complex Carbs

To ensure the weight you gain is healthy muscle mass, your diet needs adequate protein and complex carbohydrates to fuel your workouts and recovery.

Protein-Rich Options

Red Meats: Fatty cuts of beef or pork are high in both protein and calories. They contain leucine, an amino acid vital for muscle protein synthesis.
Eggs: A perfect balance of protein and healthy fats, with most of the nutrients concentrated in the yolk.
Salmon and Oily Fish: These provide high-quality protein and beneficial omega-3 fatty acids, which also help reduce inflammation.

Complex Carbohydrates

Whole Grains: Oats, brown rice, quinoa, and whole wheat bread offer sustained energy and fiber. Add milk and nuts to oats for a calorie-dense breakfast.
Starches: Potatoes, sweet potatoes, and winter squashes can be cooked with healthy oils and topped with cheese or other ingredients to significantly increase calorie content.

Integrating Snacks and Supplements

For those with smaller appetites, consuming frequent smaller meals and incorporating high-calorie snacks is often more effective than attempting to eat three large meals.

Strategic Snacking

Homemade Protein Smoothies: A customized shake can be a powerful way to add hundreds of calories. Combine whole milk or yogurt with a scoop of whey protein, a banana, nut butter, and some berries.
Trail Mix: A simple mixture of nuts, seeds, and dried fruit is an easy, portable, and high-calorie snack.
Full-Fat Greek Yogurt with Toppings: Add granola, honey, or fruit to boost calories and flavor.

Healthy vs. Unhealthy Weight Gain Foods


Food Type	Healthy Weight Gain Choices	Unhealthy Weight Gain Choices
Fats	Avocado, Olive Oil, Nuts, Nut Butters	Fried Foods, Pastries, Trans Fats
Protein	Red Meat, Eggs, Salmon, Full-Fat Dairy	Processed Deli Meats, Fatty Sausages
Carbohydrates	Whole Grains, Sweet Potatoes, Quinoa	Sugary Drinks, Cakes, Cookies, White Bread
Snacks	Trail Mix, Yogurt with Fruit, Hummus	Chips, Candy, Sugary Cereal Bars
Drinks	Full-Fat Milk, Homemade Smoothies	Sodas, Fruit Juice Concentrates

Conclusion

For those who find it challenging to gain weight, the strategy is not about overeating, but about smart, consistent consumption of high-calorie, nutrient-dense foods. By prioritizing healthy fats, quality proteins, and complex carbohydrates, and integrating strategic snacking, you can create the necessary calorie surplus to gain weight in a sustainable way. Always remember to combine this dietary approach with regular strength training to build muscle rather than just fat. For personalized guidance, consulting a healthcare provider or a registered dietitian is highly recommended to ensure your plan is tailored to your unique needs. With consistency and the right nutritional focus, healthy weight gain is an achievable goal.

Visit the Better Health Channel for more insights on healthy weight and muscle gain.

Frequently Asked Questions

For some, gaining weight is difficult due to a faster metabolism, which means their body burns calories at a higher rate. Genetics, higher physical activity levels, and a naturally smaller appetite can also be contributing factors.

It is always better to gain weight healthily by consuming nutrient-dense foods rather than junk food. Junk food offers empty calories with little nutritional value and can lead to future health complications, while healthy options support muscle growth and overall well-being.

For a steady weight gain, a good starting point is to aim for 300–500 extra calories per day. If you want to gain weight faster, you can increase this to 700–1,000 calories above your maintenance level, but it's important to monitor your progress.

Exercise, particularly strength training and weightlifting, is crucial for healthy weight gain. It helps build muscle mass, ensuring the extra calories you consume are used for muscle growth rather than just stored as body fat.

Easy, portable snacks include trail mix with nuts and dried fruits, cereal bars, and homemade shakes or smoothies in a travel bottle. Greek yogurt with granola and fruit is another great option.

Yes, protein supplements can be an effective and convenient way to increase your daily calorie and protein intake, especially if you struggle to eat large amounts of food. Mass gainer shakes are specifically formulated for this purpose.

To increase calories without feeling too full, focus on adding calorie-dense items to your meals, such as oils, nuts, seeds, and cheese. Drinking some of your calories in the form of homemade smoothies or milkshakes can also help.