Muscle is built by progressive training, enough protein and enough total food. Supplements are a convenience, not a requirement. Many gym-goers can reach their goals with dal, eggs, soya, milk and rice.
How much protein
Research on resistance training commonly supports around 1.6 g of protein per kg of body weight per day for muscle gain, with little extra benefit above about 2.2 g/kg. A 70 kg man would aim for roughly 110-150 g. Spread it over three or four meals.
Cheapest muscle foods
Soya chunks, eggs, dal, chana, peanuts, milk, curd and chicken (for non-vegetarians) give the most protein per rupee. Rice, roti, oats and bananas supply the carbohydrate that fuels training. Buy in bulk, cook in batches and keep a few boiled eggs or roasted chana ready.
A sample gym day (around 2,700 kcal, 130 g protein)
Breakfast: oats in milk with banana and peanuts. Lunch: rice, dal, soya chunk curry and curd. Pre-workout: banana and a glass of milk. Post-workout: 4 eggs or paneer bhurji with 2 roti. Dinner: rice or roti with chicken or chana, sabzi and salad. Adjust portions to your weight and progress.
When whey makes sense
If you regularly fall short of protein, one scoop of whey (about 24 g protein) can be a practical top-up; compare its cost per gram with soya and eggs first. Choose brands with third-party testing. Creatine monohydrate is the other well-researched option; avoid products with vague 'proprietary blends'.