If I eat less than 2500 calories a day, I lose weight.
People who work physically hard, consume thousands of calories a day, especially in cold climates.
Working hard outside in weather lower than 57 degrees F, an average man needs to consume 4,500 calories a day.
I'm planted at my desk writing software from 8 AM to midnight exclusive of 60 to 90 minutes to go to dinner with my wife. Mowing the lawn is the upper limit of physical labor during the Summer. Shoveling snow off the driveway in the Winter. I have to keep my inputs limited to match my activity level. Currently, 5 ft 11 in, 155 lbs. My daily protein target is 92 grams. Carbs 122 grams. Fat 40 grams. I often miss my carb target...sometimes as little as 40 grams.
Pocatello, ID can be a cold climate. Lowest on my property since 2000 was -27F. It's common to have a week near -15F in early December. It's a bit warm this year. We should be subfreezing for the last 2 weeks of October in preparation for the first snow accumulation on Oct 31.