Should You Eat More If You Are Skinny? A Healthy Guide to Weight Gain

October 19, 2025 •

4 min read

According to a 2023 study published in GoodRx, having a low body weight can carry real health risks, such as a weakened immune system, weakened bones, and nutrient deficiencies. This challenges the common assumption that being skinny automatically equates to being healthy. The question of whether you should eat more if you are skinny depends on your individual health needs and goals.

Quick Summary

Many skinny people may need to increase calorie intake for optimal health or to build muscle. This guide explains how to gain weight healthily by focusing on nutrient-dense foods, a moderate calorie surplus, and strength training. It outlines risks of being underweight and provides practical tips for a balanced diet.

Key Points

Check Your Status: Being skinny doesn't automatically mean you're healthy; assess your overall body composition and nutritional intake.
Create a Calorie Surplus: To gain weight, you must consume more calories than you burn daily, ideally with an increase of 300–500 extra calories.
Choose Nutrient-Dense Foods: Prioritize healthy, high-calorie foods like nuts, avocados, and whole grains over high-sugar junk food to ensure healthy weight gain.
Eat More Often: If a small appetite is an issue, switch to 5–6 smaller meals and snacks throughout the day to boost your overall calorie intake.
Lift Weights: Combine a calorie surplus with regular strength training to build muscle mass, rather than accumulating unhealthy body fat.
Prioritize Protein: Ensure adequate protein intake (1.2–2g per kg of body weight) to support muscle growth and repair.
Consult a Professional: For a personalized and safe weight gain plan, talk to a doctor or registered dietitian.

The Myth of the "Healthy Skinny"

For many, being thin is seen as the pinnacle of health and fitness. However, this is a dangerous misconception. Being underweight or having a low body mass index (BMI) does not guarantee good health and can pose several significant risks. Some people are genetically lean but still have poor eating habits, leading to a condition sometimes called "skinny fat"—where a person has a low body weight but a high percentage of body fat and low muscle mass. This imbalance can increase the risk of chronic diseases like diabetes and heart disease, just as in overweight individuals.

Being underweight can weaken your immune system, leaving you more susceptible to infections. It can also lead to nutritional deficiencies, which cause low energy levels and impact bone health. For women, it can disrupt menstrual cycles and affect fertility. Therefore, addressing the need to gain weight, if clinically necessary, is a crucial step toward overall well-being.

How to Safely Increase Calorie Intake

To gain weight in a healthy way, you must consume more calories than your body burns, known as a calorie surplus. The goal is to gain weight gradually and healthily, not to pack on unhealthy body fat with junk food.

Calculate Your Needs

For a steady and safe weight gain of about 0.5–1 pound per week, adults can aim for an additional 300 to 500 calories per day above their maintenance level. To gain weight faster, a surplus of 700–1,000 extra calories per day may be appropriate, but it's important to monitor progress and adjust as needed. You don't have to count calories forever, but tracking for a few weeks can give you a solid baseline.

Focus on Nutrient-Dense Foods

Not all calories are created equal. Filling up on empty calories from sugary drinks and processed snacks will likely lead to unhealthy fat gain. Instead, choose nutrient-dense, high-calorie foods that provide essential vitamins and minerals. This approach ensures you're fueling your body with quality nutrition while increasing your overall caloric intake.

Eat More Frequently

If you have a small appetite, eating three large meals can be challenging. A more effective strategy is to eat five to six smaller, more frequent meals throughout the day, with healthy snacks in between. Setting a schedule can help you stay consistent, even if you don't always feel hungry. A good night's sleep is also important for muscle growth and recovery.

Your Plate for Healthy Weight Gain

Building a balanced diet for weight gain involves focusing on the right macronutrients: protein, carbohydrates, and healthy fats. Each plays a vital role in fueling your body and building muscle mass.

Protein: Essential for building and repairing muscle tissue. Aim for 1.2–2 grams of protein per kilogram of body weight.
- Sources: Eggs, chicken breast, lean beef, fish (like salmon), dairy (milk, cheese, Greek yogurt), legumes (beans, lentils), and protein powders.
Complex Carbohydrates: Provide energy for workouts and daily activities. They also help replenish muscle glycogen stores.
- Sources: Whole-grain bread, rice (especially brown rice), oats, quinoa, sweet potatoes, and starchy vegetables.
Healthy Fats: The most calorie-dense macronutrient, providing 9 calories per gram. Adding healthy fats is an easy way to increase your calorie intake.
- Sources: Nuts, seeds, nut butters, avocados, and olive oil.

Quick weight-gain tips:

Add nut butters to oatmeal or smoothies.
Use full-fat milk instead of skim in drinks or cereals.
Sprinkle cheese, nuts, or seeds over meals.
Snack on dried fruit, trail mix, or high-protein yogurt.
Drink nutrient-dense smoothies with protein powder, milk, and fruit.
Cook with healthy oils like olive or avocado oil.

Strength Training for Muscle Mass

Simply eating more without exercise can lead to gaining unhealthy body fat. Resistance or strength training is crucial to ensure that the extra calories are converted into muscle tissue, not just stored as fat. Aim for two to four workouts per week that target all major muscle groups. Compound exercises like squats, deadlifts, and bench presses are particularly effective for stimulating muscle growth.

Weight Gain Strategies: Healthy vs. Unhealthy

Choosing the right approach is vital for long-term health. The table below outlines the contrast between healthy and unhealthy weight gain methods.


Aspect	Healthy Weight Gain	Unhealthy Weight Gain
Calorie Source	Nutrient-dense foods like whole grains, nuts, and lean proteins.	Empty calories from sugary snacks, fast food, and processed junk.
Exercise	Incorporates strength training to build muscle mass.	Relies solely on diet, leading to increased body fat and potential health issues.
Macro Focus	Balanced intake of protein, healthy carbs, and healthy fats.	Often high in unhealthy saturated fats and refined sugars, lacking essential nutrients.
Health Outcome	Increased muscle mass, stronger bones, improved energy levels, and better overall health.	Higher risk of heart disease, diabetes, inflammation, and other chronic conditions.

Conclusion: Prioritize Health, Not Just Weight

For individuals who are clinically underweight or wish to build muscle, the answer to "should you eat more if you are skinny?" is often yes. However, the key lies in the quality of what you eat, not just the quantity. Combining a moderate calorie surplus from nutrient-dense foods with a consistent strength training routine is the most effective and safest way to achieve your goals. The aim is to build a healthier, stronger body, not just a heavier one. If you are struggling with weight gain or have concerns about your health, it is always best to consult a healthcare professional or a registered dietitian for a personalized plan.

For more detailed information on specific healthy foods for weight gain, explore additional resources on Healthline.

Frequently Asked Questions

While junk food is high in calories, it is low in nutritional value and can lead to unhealthy fat gain and other health problems. Focusing on nutrient-dense, high-calorie foods is a healthier and more effective strategy.

For gradual and healthy weight gain, aiming for an extra 300–500 calories per day is recommended. For faster gain, a surplus of 700–1,000 calories might be used, but this should be monitored.

Resistance or strength training is most effective for building muscle mass, which is a healthier way to gain weight than just adding body fat. Exercises like squats, deadlifts, and bench presses are beneficial.

Yes, some people may have a naturally faster metabolism or genetics that make it harder to gain weight. However, this doesn't negate the need for a consistent calorie surplus to see results.

If you have a small appetite, try eating smaller, more frequent meals and incorporating calorie-dense snacks like nuts, dried fruit, or smoothies between meals. You can also add calorie boosters like olive oil or cheese to your food.

Yes, being underweight can lead to a weakened immune system, nutritional deficiencies, osteoporosis, infertility in women, and an increased risk of complications during surgery.

To ensure you gain muscle, combine your calorie surplus with a regular strength training program. Focus on getting enough protein to fuel muscle growth and repair. Tracking your body composition can also help monitor progress.