Most people who think they're "hard gainers" really aren't. There's an easy way to find out for sure. You need to calculate your TDEE and then meticulously track how many calories you're actually consuming.

Your BMR (Basal Metabolic Rate) is the amount of energy your body burns just to stay alive at rest. Your TDEE (Total Daily Energy Expenditure) includes your BMR plus all the calories you burn from daily life and exercise. While most online calculators give you an estimate, the only way to find your true TDEE is by tracking your food intake against your weight changes over a few weeks. For a deeper dive, see this accurate TDEE calculator.

After step2, your TDEE will be dead on center, not adjustment needed

TDEE is the matenance calories, if you eat at matenance your weight will not change if you average it over 3 weeks which should take out water weight fluctations.

If you eat more than matenance, you gain weight

if you eat less than matenance, you lose weight.

Weight gain or lost will be some part fat, some muscle, depending on training/diet

Most beginners don't track calories because it seems "difficult" at first, much like learning to ride a bike. Once you get the hang of it, though, it becomes second nature and you won't even have to think about it. Don't rely on ChatGPT for calorie counts it's off by 10-40% on average. Instead, get a cheap food scale and a set of measuring spoons or cups. Always weigh your ingredients raw before cooking for the most accurate numbers. Use the free version of Cronometer to log the raw weights and scan barcodes on packaged foods. Over time, you'll develop an intuition for portion sizes and won't need to be so meticulous. If you have a predictable daily routine, you can also create a set meal plan with your target macros and calories and just stick to that without manual tracking. For a more detailed walkthrough, check out this free resource on the topic.