Food nutrition labels are based on a 2,000 calorie diet. But some people say that adults average a 2,500 calorie diet, is that true? Others also say that very active people may need 4,000 calories.
Also, there is something that I don’t quite understand. If someone intakes 2000 calories each day and uses 2000 calories each day,
would they slowly gain weight if they took in 2001 calories a day, or
would there body use that extra calorie for some reason even if it didn’t need it instead of storying them all up over time? Because I figure the numbers change a little bit everyday.
Adult activity and metabolisms vary depending on the individual. 10-13 calories per day per lb of maintained body weight is about average for most male and (non-pregnant) female adults 25-55 years old.
2500 +/- calories per day would be OK for a relatively active 200 lb man to maintain his weight. A woman of medium height would slowly get fat as hog on a diet of 2500 calories per day unless she was a pro athlete of some kind.
Calorie requirements vary depending on a person’s size, age, and activity level. There’s a calorie calculator at Nutrition.com that will estimate the number of calories you need to maintain your weight.
It takes about 3500 unused calories (a loose estimate) to gain a pound of weight. If someone takes in just a few more calories a day than he needs, he will indeed slowly gain weight unless he becomes more active and uses those extra calories.
This online Harris-Benedict Metabolic Calculator for daily caloric requirements is based on the Harris-Benedict Metabolic formulas and is very accurate.
2000 calories is more than enuff for most people. By active people they mean professional athletes. I can guarantee you, I don’t know anyone that needs more than 2000 calories. Myself I don’t eat more than 1800 a day. I run between 1 -2 hours a day work out with weights 6 days a week and I don’t lose weight. I maintain.
I was reading an article in Psychology Today about the BMI and how people feel cheated by it. Bascially Americans were told exercise 30 minutes a day 3 days a week and you’ll be fine.
Now we find out it is 60 minutes at high heart rate 5 times a week to have benefits. And people feel cheated.
“As recently as 1995 health guidlines permitted weight gain of several pounds among the middle aged. Now scientist believe this isn’t healthy. One researcher noted the change in recommended guidelines recalssified him from ‘normal’ to ‘overweight’ His conclusion was that the new guidlines weren’t at fault he really did need to lose a few pounds.”
A great guidline is take your weight and multiply by 11.5 that is the calories an average joe needs to stay current.
Americans for some reason don’t realize you don’t need a lot of food to live. I am 39 and in great shape and am proof of that.
I had a boss that complained his diet was tough. Tough? He ate more at lunch than I did all day. Another co-worker was constantly dieting. For almost 4 years I worked with her, she never lost a pound. Who are you kidding?
People always think it is magic how I stay in shape. No it is working out and not eating like a pig. It IS hard. But think about it.
If you sleep, get up, ride the subway to work. Type at a computer for 8 hours, walk to the subway go home, wash your clothes and go to bed or similar activites you are BARELY using more calories than sleeping all day. Take this in consideration a KING SIZED fries and Whopper meal with a regular coke is around 1900 or 2000 calories. For one meal?
Now wonder we think we need a lot to live. Starbucks over 500 calories for a Venti Mocha Latte. Good but 500 calories???
I think all of these numbers seem to be coming in on the low side for high-actvity people.
I typically eat close to 3000 calories per day and I weigh 145-150, 6’1", and I’ve actully recently lost weight since going to college. In any given week, I usually run for about 4 hours and ride close to 5 hours on a bike. Just in pure energy output this comes close to a thousand calories a day.
Jan Ulrich and most pro-cyclists consume close to 8000 calories a day.
there are many factors that influence your caloric needs, the ones i can think of are
1 - Lean Body Mass ( Your total body mass, minus the fat you have, your fat doesn’t require any calories to sustain, your other tissues do )
2 - Your Age ( Younger people need more calories cuz their metabolism is faster, i would probably say after mid twenties or so it would start slowing down )
3 - Your Unique Metabolism ( Thyroid Hormone levels, Leptin Levels, Leptin Sensitivity etc … these are individual things which affect how your body uses energy. Some people shoot Thyroid hormone to lose weight, this is illegal and dangerous but effective cuz it jacks up your metabolism )
4 - Activity Level ( Working out doesn’t just burn calories directy through work performed, but also indirectly through hormonal responses causes your overall metabolism to speed up )
5 - Steroids ( Steroids are somewhat thermogenic, they increase your energy expenditure ). This is also one of the reasons why women don’t need quite as many calories as men.
6 - how you have been eating lately ( if you have been dieting hard, your metabolism will be slowed, and vice versa. that is the body will attempt to stabilze your weight. however, it is not healthy to rely on your body to do so, you should take care of this yourself )
summary:
a 120 pound woman who works in a cubicle all day probably needs about 1500 calories. a 250 pound football player that does 2 hours of practice per day and shoots steroids needs about 4000 calories or so 
FWIW, I range between 120 and 126 pounds, and have done so for about 1.5 years now, and 800-900 calories a day is a “maintenance diet” for me. But then, I’m the lightest person, female or male, in my group of a couple hundred people.
My co-workers eat more than that in the daily morning “doughnut run”. I’ve personally witnessed people eat perhaps 5000 calories in a day, and know people at work that eat perhaps 3-4000 a day like clockwork. And, of course, nearly every single woman and man in my office, barring a handful, is either obese or borderline obese.
I’m just saying that from experience I know that people really don’t need that much in the way of calories to survive and prosper, given that health and nutrition are watched as well.