Q:

Do i really have to eat this much for building muscles?

The calorie calculator tells me to eat 2700.
My friends/forums tell me to eat 3000-5000 to bulk up. 
I'm student who us very lightly active. Most of the time I read or sitting at the desk. 
I do go to the gym 5 times a week. And now I do take 2600 cal and 200gram protein daily. But I'm getting fatter and the belly is growing. 
If I sink it down to 2100 cal, will this affect my muscle growth? What should I do? How much to eat? I need maximum muscle growth and minimum body fat.
23yo. Male. 1 year experience. I do run every night for 2-5km. 
5 days per week for weight lifting. 174 cm. 82 kg.

A:

Calorie calculators can't tell you exactly how many calories you need to eat -- they're making a lot of assumptions about your metabolism, activity level, etc.  While tools like the Harris Benedict Formula are useful, they are generalizations -- everyone is different.  Not to mention, your activity level and metabolic rate will vary from week to week due to all kinds of stimulus you may not be able to control (stress levels, weather, relationships, sleep, and so on). You should use a calorie calculator as a baseline and do your own study from there. 
The easiest way to do this is to buy a skin fold caliper (~$8 on amazon) and start a spreadsheet.  Use the calipers to measure your bodyfat, and weigh yourself every day or week.  Keep track of how many calories you're eating using something like fitday (or tallying the calories yourself).  Keep this data logged and make adjustments on a weekly basis.  
You can dial in your daily caloric needs by observing for a couple of weeks.  If your weight and bodyfat don't fluctuate over the duration, you can average the number of calories you ate to determine your daily needs.  At that point, you can increase your calorie consumption by about 300-500 per day for the duration of your bulk.  If you find you are putting on too much body fat, you can tweak these numbers.
I realize that reading "couple of weeks" can be off-putting because we want a solution right now.  But remember that there is no instant gratification in fitness.  You can't get a six pack overnight, nor can you squat 405 overnight.  Be scientific, be patient, and your results will reflect your effort.

A:

There are many reasons that bulking diets fail but here are a few of the most common reasons:
1. Calories are not high enough and putting on muscle mass fails.
2. Calories are too high and macros are wrong. This in turn leads to putting on fat as well as muscle.
3. You are bulking, not cheating. Cheat days can be factored in, but your food choices should still be healthy. All diets, whether cutting or bulking, need to be monitored. This means that watching your insulin spikes and the type of carb you consume.
4. You are what you eat, it’s that simple. To simplify, you eat crap and you will look like crap.
Harris Benedict Formula for Calorie Calculations
“The Harris Benedict equation is a calorie formula using the variables of height, weight, age, and gender to calculate basal metabolic rate (BMR). This is more accurate than calculating calorie needs based on total body weight alone. The only factor it omits is lean body mass and thus the ratio of muscle-to-fat a body has. Remember, leaner bodies need more calories than less leaner ones. Therefore, this equation will be very accurate in all but the very muscular (Harris-Benedict will under-estimate calorie needs) and the very fat (Harris-Benedict will over-estimate calorie needs).”
That being said, there are is no concrete number of daily calorie intake your body needs, however using this formula will give you can idea of what you do need.
Harris Benedict Formula for Men - Step 1
BMR = 66 + (13.7 X weight in kilos) + (5 X height in cm) - (6.8 X age in years)
Example:
You are 25 years old
You are 6 feet tall
Your weight is 220 pounds
Your BMR is 66 + (1370) + (914) - (170) = 2180 calories
Harris Benedict Formula for Men - Step 2
To determine your total daily calorie needs (aka TDEE) multiply your BMR by the appropriate activity factor, as follows:
If you are Sedentary - little or no exercise
Calorie-Calculation = BMR X 1.2 
- If you are Lightly Active (light exercise/sports 1-3 days/week)
Calorie-Calculation = BMR X 1.375 
- If you are Moderately Active (moderate exercise/sports 3-5 days/week)
Calorie-Calculation = BMR X 1.55 
- If you are Very Active = BMR X 1.725 (hard exercise/sports 6-7 days/week)
Calorie-Calculation = BMR X 1.725 
- If you are Extra Active (very hard daily exercise/sports & physical job or 2X day training)
Calorie-Calculation = BMR X 1.9 
Total Calorie Needs Example
If you are lightly active, multiply your BMR (2180) by 1.375 = 2997
Your total daily calorie requirement is therefore 2997 calories.
This is the total number of calories you need in order to maintain your current weight. 
If you want to gain body weight, you must consume more calories than you burn, pretty straightforward. So now we know that you need extra calories to gain weight. So what should these calories be comprised of?
The BASICS-
1. Carbs - carbohydrates are a very helpful macronutrient when you are trying to gain lean mass. Meals should be comprised of slow burning complex carbs that are low on the glycemic chart. Some good examples of low glycemic carbs are brown rice, yams, and oatmeal. Others may include whole wheat bread, whole wheat pasta.

Protein - For bulking a good rule of thumb is 4g-6g of protein per kilogram of lean bodyweight. You should take in a good portion of your protein in the source of real meals, avoid intaking too many shakes. Examples of food with high protein bioavailability is egg whites, lean steak, and chicken breast.
Fats - EFA’s (Essential Fatty Acids) are extremely important in any diet. Examples of good sources of fat are flax oil, nuts, salmon, olive oil.
The separation of Carbs and Fats - It is often when you eat items and with what you eat them that is more important than what you are eating. Remember that when you take in certain carbs you can spike your insulin levels. If you are taking in fats when your insulin is spiked you are allowing the basic laws of physiology to act out, and you allow for a higher propensity for fat storage. Separation is key. The sample diet will give a good example of how to separate them.
Supplements - Glutamine: Helps prevent catabolism. Best used in dosages of 10grams daily, 5 grams before cardio and 5 grams at another interval, but not after workout as it fights for absorption with the glutamine peptides in whey. Creatine: Unlike while cutting, creatine can be used while bulking since the water retention from its use will not be an issue since you are “bulking”. In the body, creatine is synthesized from the amino acids glycine, arginine and methionine. Taking supplemental doses of creatine monohydrate can increase muscle creatine and phosphocreatine (PC) concentrations by up to 40%. These increases can lead to improvements in muscle energy production and recuperation.
Cheating - Cheating is essential. Why? Remember, the body runs on homeostasis and it likes to keep balance. After eating so well after a week, your body begins to adjust and lean mass gain / fat burning over time will not be as rapid. The other extremely important aspect is mental sanity. So many diets crash and fail because people don’t give themselves a chance to breath. Shoot for a cheat meal, not an all out binge. A fast food value meal can be 2,000 calories. Eat that 3 times on one day, and you’ve consumed 6,000 calories. And that’s not good in any case.
Cardio - Cardio works the most important muscle of all – your heart. Not only that but doing cardio 3 times a week will help keep the fat you will gain in this diet to a minimum. The proper cardio for burning fat is done by staying in your target heart rate for fat burning which is 65-70% of your max heart rate for a period of 45-60 minutes.

Sample Diet: 
Based on the Harris Benedict formula above, our friend here needs 2997 calories a day to maintain his current weight. So in order for him to gain 1 pound a week, we need to increase his calories to right around 3500 a day since that will yield 3500 calories over his maintenance numbers needed for the week.
Meal 1: Pro/Carb
8 Egg Whites, 1 Scoop Of Whey Protein, 1 cup oatmeal
50g protein / 54g carbs / 5g fat
Meal 2: Pro/Fat
Lean Ground Beef, ¼ cup swiss cheese, green veggies
55g protein / 2g carbs / 20g fat
Meal 3: Pro/Carb 
Chicken Breast, 1 and a half cup Brown Rice
55g protein / 64g carbs / 3g Fat
Meal 4: Pro/Fat
2 Cans of Tuna, 1 Tbsp Full Fat Mayonnaise, Veggies
60g protein / 2g carbs / 13g Fat
Meal 5: PWO Nutrition
2 Scoops Whey Protein / 80g of Dextrose
40g protein / 80g carbs / 0g fat
Meal 6: PPWO
Boneless Skinless Chicken Breast, ½ cup Brown Rice (Measured Uncooked)
50g protein / 70g carbs / 3g fat
Meal 7: Pro/Fat
Lean Protein of your choice, 2 Tbsp Natural Peanut Butter
50g protein / 5g carbs / 18g fat
Meal 8: Before Bed
3 Scoops of Whey Protein, 1.5 Tbsp. Flax Seed Oil
60g protein / 3g carbs / 21g Fat
That turns into approximately 420 grams protein, 250 grams Carbs, and 83 grams of fat. This is roughly 3500 calories

