Welcome to HCM
first of all you have to increase your appetite.
Avoid going long periods of time without eating.
Gradually eat more food each day.
Keep a food diary.
Exercise It will help you build muscle and increase your appetite. Your body may compensate or even overcompensate for the Calories that you burn exercising.
Consume a variety of different foods at mealtime.
Choose high-Calorie, high-nutrient foods that are less filling.
Make mealtime pleasant.
Use larger cups, plates, bowls.
Alternatively, try eating smaller portions if a large meal seems daunting.
Drink more Calories. Have a caloric beverage with every meal.
this is also for weight gain and take high protein like dairy products like milk, cottage cheese,nuts,protein bars.
Thankyou.

Dear rajat,

Welcome here. I totally agree with Dr. Disha. I just want to add that as you asked about Endura mass. Its always good to increase weight naturally , avoiding any supplements.
Consuming protein powder in excess or using it as a replacement for other nutritious foods, can be excessively detrimental to your health.Always consult your health care provider before starting any kind of protein supplement. Reason being some protein powders contain higher levels of cholesterol.
if your diet in not deficient in protein then by taking protein powder you may be doing your body more harm than good. If your protein consumption is much more than required then it can cause constipation, diverticulitis, heart disease or liver and kidney problems. It should be used with proper care with kidney and heart patients. Healthy adults do not need any more than 50 to 175 grams of protein daily, or about 10 to 35 per cent of their total calorie intake.

I hope this information is useful for you.

Thanks