The Best Food for Underweight Individuals to Gain Healthy Weight

November 16, 2025 •

4 min read

According to the Centers for Disease Control and Prevention, approximately 1.6% of adults in the United States are underweight, highlighting a significant but often overlooked health concern. Finding the best food for underweight individuals is crucial for gaining weight safely and improving overall health, not just adding pounds.

Quick Summary

This article outlines a strategic approach to healthy weight gain by focusing on nutrient-dense, calorie-rich foods. It details essential macronutrients, provides food lists, and offers practical tips for increasing caloric intake safely. The guide also emphasizes balancing proteins, carbs, and fats to support muscle development and overall well-being.

Key Points

Prioritize Nutrient-Dense Calories: Focus on high-calorie foods that also offer significant nutritional benefits, not just empty calories from junk food.
Increase Protein and Healthy Fats: Incorporate more protein-rich foods like meat, eggs, and legumes, and healthy fats from avocados, nuts, and oils to build muscle and increase calorie intake.
Eat Frequently: Aim for 3 balanced meals and 2-3 nutrient-dense snacks throughout the day to ensure a consistent calorie surplus.
Incorporate Calorie-Boosting Drinks: Utilize smoothies, milkshakes, and full-fat milk between meals to add extra calories without feeling overly full.
Add Strength Training: Pair your diet with resistance exercises to promote muscle growth and healthy weight gain instead of storing fat.
Listen to Your Body: Monitor your progress and adjust your intake as needed, and always consult a doctor or dietitian if you have underlying health concerns.

Understanding Healthy Weight Gain

Healthy weight gain, unlike simply eating junk food, involves a balanced increase in calorie intake from nutritious sources to build muscle mass and body fat. Consuming an extra 300 to 500 calories per day from high-calorie foods can facilitate a gradual and safe weight increase. The key is to prioritize nutrient density over empty calories.

The Importance of Macronutrients

To effectively and healthily gain weight, focusing on the right balance of macronutrients is essential. A higher intake of proteins, carbohydrates, and healthy fats is the foundation of a successful weight gain diet plan.

Protein: Essential for building and repairing muscle tissue. Good sources include eggs, meat, fish, and legumes.
Carbohydrates: Provide the necessary energy for the body and muscles. Whole-grain bread, rice, and oats are great options.
Healthy Fats: Crucial for increasing calorie intake and overall health. Examples include nuts, seeds, and avocados.

The Best Foods for Underweight Individuals

To make your weight gain journey effective and healthy, consider incorporating the following foods into your diet regularly.

High-Calorie & Nutrient-Dense Foods

Here is a list of excellent food choices for gaining weight:

Nuts and Nut Butters: Almonds, walnuts, and natural peanut butter are calorie-dense and rich in protein and fats.
Avocados: A superfood packed with healthy fats, fiber, and vitamins.
Full-Fat Dairy: Full-fat milk, Greek yogurt, and cheese are great sources of protein, calcium, and fat.
Eggs: A budget-friendly source of high-quality protein and healthy fats.
Red Meat: Lean beef and fatty cuts of lamb provide protein and iron, essential for muscle building.
Oily Fish: Salmon and other oily fish are rich in protein and healthy omega-3 fatty acids.
Whole Grains: Brown rice, oats, and whole-grain bread offer complex carbohydrates for sustained energy.
Starches: Potatoes, sweet potatoes, and legumes are good sources of carbohydrates and calories.
Dark Chocolate: Provides calories, antioxidants, and a dose of magnesium.
Dried Fruits: Naturally high in sugars and calories, they are a great energy boost.

Strategic Meal and Snack Ideas

Instead of just increasing portion sizes, strategic eating throughout the day is key. Aim for 3 meals and 2–3 snacks to maintain a consistent calorie surplus.

Breakfast: Add an extra slice of whole-grain toast with peanut butter to your regular breakfast.
Mid-Morning: A cup of full-fat Greek yogurt with nuts, seeds, and dried fruit makes for a great snack.
Lunch: Combine brown rice with lean chicken or fish, topped with avocado slices.
Mid-Afternoon: Prepare a protein-rich smoothie with milk, nut butter, and bananas.
Dinner: A hearty serving of chicken curry or fish with starchy vegetables like potatoes.
Before Bed: A small portion of cottage cheese with dried fruit can provide slow-digesting protein.

Comparison of High-Calorie Foods for Weight Gain

To help you decide which foods best fit your diet, here's a comparison based on their nutritional benefits.


Food Item	Primary Benefit	Calorie Density	Protein Content	Healthy Fats	Other Notes
Almonds	Protein & Healthy Fats	High	High	High	Great for snacks and toppings.
Avocado	Healthy Monounsaturated Fats	High	Medium	Very High	Excellent on toast or in salads.
Full-Fat Greek Yogurt	Protein & Calcium	High	High	High	Ideal for smoothies and snacks.
Brown Rice	Complex Carbohydrates	Medium	Medium	Low	Staple for energy, pairs well with protein.
Salmon	Omega-3s & Protein	Medium-High	High	High	Supports heart and brain health.
Lean Red Meat	Protein & Iron	High	High	Medium	Essential for muscle building.
Eggs	Complete Protein	Medium	High	High	Extremely versatile and nutrient-dense.

Creating a Calorie Surplus

To achieve a healthy weight gain, you must consume more calories than your body burns, known as a calorie surplus. This surplus should come from nutrient-dense foods rather than processed junk food. For example, instead of a sugary soft drink, opt for a banana smoothie with whole milk and peanut butter, which provides more sustained energy and nutrients.

Incorporating Healthy Habits

In addition to dietary changes, adopting certain lifestyle habits can support your weight gain goals.

Eat Smaller, More Frequent Meals: This can be less daunting for those with smaller appetites and helps maintain a steady energy supply.
Use Larger Plates: A simple psychological trick to encourage slightly larger portion sizes.
Drink Calories Wisely: Milkshakes, smoothies, and fruit juices between meals add calories without filling you up too much before your next meal.
Strength Training: Resistance exercises help turn the extra calories into muscle rather than just fat.

Conclusion

Gaining weight healthily requires a strategic and consistent effort that goes beyond simply eating more. Focusing on nutrient-dense, high-calorie foods like nuts, avocados, and full-fat dairy, combined with adequate protein, carbohydrates, and healthy fats, is crucial. By adopting these dietary habits and incorporating regular strength training, individuals can achieve their weight gain goals safely and effectively while improving their overall health. For tailored advice, always consult a healthcare provider or a registered dietitian.

For more detailed nutritional information and guidelines, visit the Academy of Nutrition and Dietetics website.

Frequently Asked Questions

For healthy weight gain, whole milk is generally recommended over skim or low-fat milk. It provides more calories, protein, and calcium, helping to boost your daily intake effectively.

Yes, nuts and nut butters are excellent for weight gain. They are extremely calorie-dense and packed with healthy fats, protein, and fiber. A small handful can provide a significant number of calories.

To increase calories without feeling too full, focus on nutrient-dense, high-calorie drinks like smoothies made with milk, nut butter, and bananas. You can also add extra calories to meals with healthy fats like olive oil or cheese.

Red meat is high in protein and can help build muscle mass. However, consume it in moderation and choose leaner cuts, as excessive intake of fatty meats is linked to health risks. Balance your diet with other protein sources like fish and eggs.

Yes, exercise, particularly strength or resistance training, is crucial. It helps ensure that the extra calories you consume are converted into muscle mass rather than unhealthy fat storage.

The best snacks are calorie-dense and nutritious. Consider options like trail mix with nuts and dried fruit, whole-grain toast with avocado, or full-fat yogurt with granola.

Start gradually by adding an extra 300-500 calories per day from healthy, nutrient-dense foods. Increase the frequency of your meals and include calorie-dense snacks. It's best to consult a healthcare provider or dietitian for a personalized plan.