In this crazy world, sometimes up is down, down is sideways — and numbers we thought were grounded in science turn out to be more or less made up.
That’s the problem with the 2,000-calorie diet.
Turns out, 2,000 was never a magic number when it comes to daily calories. It was never even the most accurate number. It was just the number that made it through committee.
The 2,000-calorie diet was invented to simplify nutrition labels.
The history goes like this: In the 1990s, when the FDA was standardizing nutrition labels for U.S. food, they wanted to include a benchmark number for daily calories. Unfortunately, no such number existed. So they turned to data from public surveys, in which people had self-reported how many calories they ate per day. (Were these accurate reports? Fingers crossed.)
They got a wide range of answers, from 1,600 to 3,000 calories. But nutrition labels can only fit so much information! Ultimately, the committee decided to keep it simple, if not exactly accurate. They wanted just one number.
Technically, the survey average was about 2,400 daily calories — but 2,000 won the day. It was easier to remember, and proponents argued that it was better for people to eat too little than too much.
“It was essentially a compromise number that is nice and rounded,” says Dr. St. Pierre. “Which puts into perspective how badly we have managed calories and serving sizes as a society.”
If you’ve been planning your portions around a 2,000-calorie diet, you may be eating too much — or too little.
In hindsight, the most helpful part of the U.S. nutrition label is likely the footnote: “Your daily value may be higher or lower depending on your calorie needs.”
“The 2,000-calorie diet probably actually applies to a very small section of the population,” says Dr. St. Pierre. “Diet and portion sizes are very individualized.”
For instance, if you’re 4’11” and 130 pounds, you might need just 1,500 calories — depending, of course, on your lifestyle, genetics and lots of other factors. If you’re 7’2” and 350 pounds, you could need closer to 3,000 calories.
Here’s how to estimate how many calories you should consume in a day.
For a rough guess, you can plug your height, weight and activity level into an online calculator. However, such calculators don’t take into account personal details like genetics.
For a more evidence-based approach, you can track your weight along with calorie consumption using an app like MyFitnessPal. Over time, you may notice trends that show how many calories cause you to gain, lose or maintain weight.
But this isn’t a perfect solution, either.
“For example, certain foods lead to more weight gain than others, even when they contain the same amount of calories,” says Dr. St. Pierre. “Just looking at calories can give you an incomplete picture.”
The best way to find out if you should be on a 2,000-calorie diet? Ask your doctor.
Your doctor will be able to look at the whole picture, including nutrition and genetic factors you can’t spot on your own.
They can also advise you on the best diet and lifestyle changes for you — saving you time, and keeping you healthy.
“The safest and most sustainable way to achieve your nutrition goals is to involve an expert,” says Dr. St. Pierre. “There’s so much misinformation out there. We can make sure you’re on a path that will actually have a long-term impact — and that’s right for you.”