I don't like to think about my caloric intake (energy input) in relation to what other people's caloric intake is. It's starting from a reference point that doesn't serve me reliably and becomes very easy to say things such as, I like to eat or have a slow metabolism compared to someone else. But if you think about it, what other people can eat and not gain weight shouldn't matter to you one bit. What happens to you when you eat and how much you eat should matter. For example, it's like comparing your fuel efficiency in relation to another vehicle. (Your metabolism) Let's say that you are a small Smart car and the other vehicle is an F-150 pick up truck. Of course these two vehicles have different energy requirements to move the same distance therefore you don't put the same amount of energy (gasoline) in both vehicles otherwise eventually the Smart car will be overflowing with gasoline since isn't burning enough. So someone with a fast metabolism would be like the F-150 truck and someone with the slow metabolism would be like the Smart car. To think that the two should have the same fuel requirement seems silly whereas people always have an example of someone who can eat more and still stay slim. Maybe they are a truck internally and just need a lot more fuel than you or I but it doesn't mean we should eat similarly to them.

People just need help to find what works for them and for a majority of people who don't have hormone imbalances starting with energy in = energy used personally is going to get them very far in their weight control and just generally understanding what happens to their bodies in relation to food intake. We focus too much on anything but energy intake (this food is a super food, and this is healthy and that isn't). I'm not saying they are not important but if you want to make quick health improvements to a large group of people, starting from energy input to output is more effective.

I used to not be able to put on mass (hard gainer). What I found was that I wasn't eating as much as I thought and really to gain muscle mass and not just mass you then need to not only be in a caloric surplus you need to look a level deeper at your macros and increase your protein in take. If it fits your macros diet would get you close to a body that you are happy with as long as you tweak your macros to what you want to accomplish.

Also, healthy foods do have merit with their micros but again if you don't have hormone issues you can eat what is untraditional considered unhealthy foods, such as McDonalds, and not put on weight or even lose weight as long as you control for caloric intake. The hard part with unhealthy foods is controlling your calories. It is really easy to eat your daily total calories in one or two meals eating unhealthy foods (McDonalds in this example) than eating vegetables and healthier proteins and carbs (lean meats and whole grains). The Supersize me guy didn't get fat because he ate McDonalds he got fat because he ate sooo many calories. Fat Head was a bit of a rebuttal showing what happens when you try to control for calories more. Athletes are known to eat a lot of calories and don't become obese but again it's about getting your energy equation to balance or off balanced in the way you'd like. (caloric surplus to gain weight and a caloric deficit to loss weight)

There will be a lot of nuance in how everyone's bodies will respond and yes watching some metrics other than weight, like blood pressure and cholesterol , will be important in our health. Starting from a high level of just understand OUR personal energy needs and then working from there will give people a lot of benefit and make discussions easier. Because I hear so often from people that what I'm eating is unhealthy when in reality I'm within my caloric intake and within my macro makeup. Just because you eat a homemade cookie or a homemade cake doesn't make it healthier than my Snickers Bar (ooh I love Snickers). And it is so much easier to keep track of my calories when eating a Snickers bar than something homemade. It really is so easy to overeat on those treats especially during the holidays because you have no idea what the person used to bake those.