7-Day Weight Gain Diet Plan for Underweight Indians

Underweight (BMI below 18.5) is less talked about than obesity but carries real health risks: weakened immune system, poor bone density, muscle wasting, and hormonal disruption. India has one of the highest rates of underweight adults in the world — and the standard advice of "just eat more" is as useless as telling an obese person to "just eat less." You need a specific plan with specific foods, timings, and quantities.

The mistake most underweight people make is trying to gain weight through junk food — biscuits, namkeen, sugary drinks. This does add calories but not muscle or bone density. You end up with "skinny fat" — the same low muscle mass with added visceral fat, which is worse for health than being lean. The goal is to gain weight that is mostly muscle and bone — which requires a caloric surplus with adequate protein, not just empty calories.

This plan targets 2,500–2,800 calories per day — roughly 400–600 calories above what an underweight individual typically needs to maintain weight — spread across 6 eating occasions. The strategy is nutrient density: every meal and snack has to earn its place by delivering protein, healthy fat, or complex carbohydrates. Dry fruits, ghee, full-fat dairy, nuts, and legumes are the backbone of this plan.

One of the most practical challenges for underweight people is appetite — small stomach capacity means eating large meals feels impossible and often uncomfortable. The 6-meal structure solves this: instead of trying to eat 1,000 calories at lunch, you eat 400–500 calories six times across the day. Each meal is manageable but the total adds up. The plan also specifically advises against drinking water immediately before meals because it suppresses appetite — water should come 30 minutes after eating, not before or during.

The food selection focuses on calorie-dense foods that are not physically large: a tablespoon of peanut butter has 100 calories, a handful of dry fruits has 180 calories, a glass of full-fat milk has 150 calories. These are easy to add without feeling stuffed. The plan includes a banana + full-fat milk + dry fruits morning combination that functions as a natural mass-gainer — roughly 400 calories in a form that's easy on the stomach and rich in potassium, calcium, and healthy fats.

This plan is for adults with a BMI below 18.5 who want to gain weight in a structured, healthy way — not through junk food. It's also for people who have always been "naturally thin," have been recently ill and lost weight, are recovering from an eating disorder under medical supervision, or are young adults whose weight has not kept pace with their height. Parents of underweight teenagers (with appropriate calorie adjustments) may also find this useful.

Before starting a weight gain plan, it's worth ruling out medical causes of underweight: hyperthyroidism, intestinal malabsorption, chronic parasitic infection, and undiagnosed celiac disease can all cause persistent underweight. The plan assumes you're medically healthy and simply need adequate calories and protein to gain weight. If you've been underweight for years without explanation, a basic thyroid test and CBC are worth doing first.