Why is it important to eat SO much more calories when bulking?

It's all relative. If someone is bulking with 4k calories I would hope they're 250lbs at about 12-15% body fat and very active. Otherwise that many calories will lead to a lot of fat gain if sustained over a significant period of time

Anyway, the amount of calories is relative to your current body composition, size, activity level, etc. It's better to ask how many calories relative to your maintenance level should you intake to optimally gain muscle.

That said, all of it boils down to the fact that if you want to gain muscle optimally you need to take a few pretty simple steps:

1. Eat somewhere around 0.8-1 gram of protein per pound of body weight per day
2. Be in a calorie surplus somewhere around 10% above your maintenance level
3. Use a well designed, progressive, lifting program consistently

joshie4lyfe wrote: »

I get why you need to eat more to build protein, carb and fat intake, but why SO much more. People are doing bulks eating like 4000 calories, which is alot of food. Would you maintain a healthy diet but much more protein?

"So much more" would be relative to maintenance requirements as well as experience and existing size and BF%. Generally 10-20% over your maintenance is what is recommended. A novice who is low BF% is going to benefit from being higher on that range or even possibly a dirty bulk with noob gains in play. I did a dirty bulk in my early 20s because I was about a buck 35 soaking wet, skinny, sub 10% and bordering on under weight. Both the fat and the muscle were good for me and I put on about 30 Lbs or so in a year but was still relatively lean. I had an active job in the Marines so I ate...a lot...like a ton of food.

4,000 calories to bulk doesn't seem like a huge stretch to me. For myself it would definitely be a dirty bulk for sure...but I'm also 47 with a desk job...but I still maintain on around 3,000 calories per day. A younger male who is more active could easily maintain on more than that where 4,000 calories could easily fall into the range of 10-20%. My barber is a young guy (early 30s) and former amateur competitive bodybuilder. When he was bodybuilding, he also was working as a ranch hand...he told me that during that time he was eating every 2 hours and over 5,000 calories per day in order to actually put on weight consistently over the course of a bulking cycle. It wasn't a dirty bulk, he just had a very high calorie requirement just to maintain weight.

Also, some people just have no idea...they know they need more calories, but that's about it...and others are content to have the fast gains (muscle, fat, and strength) that come with a dirty bulk.