There are many theories that get tossed around in the weight loss/ weight gain science arenas. There is the old standard calories in vs. calories out theory that says if you take in more calories than you burn you will gain weight and vice versa. According to this way of thinking, you need to eat about 3500 calories above what you are burning to gain a pound. But, how do you make sure that you are gaining muscle and not fat?

Here’s where things start to get a little more complicated. A lot of the other theories flying around have to do with ratios. The ratios I am referring to compare the percentages of your diet that come from protein, carbohydrates and fat.

For muscle gain without fat loss the recommended ratio is usually 40/50/10 meaning that 40% of your total calorie intake is from protein, 50 percent is from carbohydrates and 10% is from fat. This is noticeably less fat than the weight loss ratios which usually call for a minimum of 20% fat and that may seem counter intuitive to you, but eating too much fat will actually slow down your weight gain for a couple of important reasons:

1. It fills you up more quickly so you will end up eating too few calories.

2. It is more difficult for the body to store or use as energy and actually requires more calories to process.

You need to have adequate protein
and carbohydrate intake to support the new muscle growth you are trying to achieve. The minimum protein intake for muscle repair is about 1 gram of protein for every pound of your bodyweight, but you will need to check your ratios and be sure to get about 40% of your total calories from protein.

You should track everything you eat for 2 to 3 weeks until you understand what the right amount of food and ratios look like for you can then continue eating the same way. If you stop gaining weight or lose weight, simply go back to tracking your meals until you are back on track again.

As for the “how much to eat” part…Remember that you are underweight due to a combination of a high metabolism and not eating enough. That is usually the thing the skinny least wants to hear. You probably think you eat a lot, right? Track your current food intake for a couple of days and you will likely be surprised to find out you are not eating nearly enough.

You need to be eating 5 or 6 substantial meals per day with the 40/50/10 ratio in order to gain enough weight. There are plenty of complicated formulas for figuring out exactly how many calories you should be eating in order to gain weight, but an easier method is to take your current weight and multiply that by 15 and base your caloric intake on that number. If you aren’t gaining a pound a week you should multiply your weight by 16 or 17 until you begin to see the increase you want.