How to Gain Weight Safely If Underweight
Being underweight can be just as concerning as being overweight. It may lead to weakened immunity, low energy levels, poor muscle mass, and nutrient deficiencies. The key to healthy weight gain is gradually increasing calorie intake while ensuring nutritional balance.
✔ Increase calories with nutrient-dense foods instead of junk food.
✔ Incorporate strength training to gain lean muscle rather than excess fat.
✔ Follow an NHS-backed healthy weight gain plan to avoid health risks.
📌 Check Your BMI to Determine If You Are Underweight
What is Considered Underweight?
BMI Classification for Underweight Individuals
BMI (Body Mass Index) is a common measure used to assess whether your weight is within a healthy range.
| BMI Range | Weight Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy Weight |
| 25 – 29.9 | Overweight |
| 30+ | Obese |
🔗 Use the NHS BMI Calculator to Check Your Weight
Common Causes of Being Underweight
✔ High metabolism – Some individuals naturally burn more calories than they consume.
✔ Poor appetite – Stress, anxiety, or medical conditions can reduce appetite.
✔ Medical conditions – Hyperthyroidism, diabetes, or digestive disorders can lead to unintentional weight loss.
✔ Excessive physical activity – Athletes or individuals with active lifestyles may struggle to maintain weight.
📌 Learn More About BMI Health Risks
How to Gain Weight in a Healthy Way
1. Increase Your Calorie Intake the Right Way
To gain weight, you need to consume more calories than your body burns. However, it’s essential to do this with nutrient-rich foods rather than processed, high-sugar, or unhealthy fat sources.
✔ Increase daily calorie intake by 300-500 kcal for steady weight gain.
✔ For faster results, aim for 700-1,000 extra kcal per day.
✔ Choose whole, high-calorie foods with essential nutrients.
Best High-Calorie Foods for Weight Gain
| Food Type | Examples |
|---|---|
| Healthy Fats | Avocados, nuts, seeds, olive oil |
| Protein Sources | Chicken, salmon, eggs, tofu, beans |
| Complex Carbohydrates | Brown rice, whole grain pasta, oats, quinoa |
| Dairy Products | Whole milk, Greek yoghurt, cheese |
| Calorie-Dense Snacks | Nut butter, trail mix, dark chocolate |
🔗 Find NHS-Recommended Meal Plans for Healthy Weight Gain
2. Prioritise Strength Training to Build Muscle
Simply increasing calories without exercise may lead to fat gain instead of muscle growth. Incorporating strength training exercises helps build lean muscle mass, improving body composition.
✔ Focus on resistance exercises – Weightlifting, squats, lunges, push-ups.
✔ Train at least 3-4 times per week to stimulate muscle growth.
✔ Progressively increase weights and repetitions over time.
🔗 Best NHS-Approved Exercises for Strength & Muscle Gain
3. Eat More Frequently Throughout the Day
✔ Instead of three large meals, eat 5-6 smaller meals daily.
✔ Snack on calorie-dense foods like nuts, dried fruit, protein bars.
✔ Drink high-calorie smoothies with banana, peanut butter, oats, and whole milk.
4. Improve Digestive Health for Better Nutrient Absorption
✔ Eat probiotic-rich foods like yoghurt, kefir, and fermented vegetables.
✔ Stay hydrated to improve digestion and prevent bloating.
✔ Limit processed foods, as they can disrupt gut health.
📌 Check Your BMI & Start a Healthy Weight Gain Plan
Common Mistakes to Avoid When Gaining Weight
1. Relying on Junk Food for Calories
✔ Processed foods high in sugar and unhealthy fats can lead to poor metabolic health and nutritional deficiencies.
2. Skipping Strength Training
✔ Weight gain without muscle-building exercises can result in excess fat accumulation rather than lean muscle growth.
3. Not Tracking Progress
✔ Regularly monitor weight, BMI, and muscle gain to ensure healthy progress.
🔗 Learn How to Reduce BMI if Necessary
Frequently Asked Questions (FAQs)
How Many Calories Should I Eat to Gain Weight?
✔ To gain 0.5 kg per week, aim for 300-500 extra calories daily.
What Are the Best Supplements for Healthy Weight Gain?
✔ Protein powders, creatine, and mass gainers can support weight gain but should complement whole foods.
Can Being Underweight Be Dangerous?
✔ Yes, underweight individuals may experience weakened immunity, brittle bones, and low energy levels.
📌 Use the NHS BMI Calculator to Check If You Are Underweight
Key Takeaways
✔ Increase calorie intake with nutrient-dense foods, not junk food.
✔ Combine strength training with healthy eating for lean muscle growth.
✔ Eat frequently, prioritise digestion, and track progress.
✔ Use BMI and body composition tools to assess progress effectively.
📌 Find Your Ideal Weight & Start Your Healthy Weight Gain Journey
Related Guides & Resources
✔ What is BMI?
✔ NHS BMI Chart
✔ Waist-to-Hip Ratio Calculator
✔ Best NHS-Approved Exercises for Strength & Weight Gain
