Can we get a flat belly just by running every day, without doing any crunches?

You should eat everything in moderate quantities. Try to keep your hands off oily and sweet food items. You can go through our blog to get extensive details about the diets you can try. https://www.credihealth.com/blog/low-carb-indian-diet/

The ideal weight for a 3 month old baby should be between 5-6kgs.

High triglycerides can affect your heart health and blood pressure. You should avoid sugary foods like sweet soda and desserts, fried foods like fries, processed foods like pizza, burger, chips, noodles, fatty meats like bacon, sausages, refined carbs like white bread, pastries and alcohol.