There are hundreds of calorie counting websites and apps on the internet today, but a new one created by the federal government called the Body Weight Planner ( is backed by science.

What makes this calorie counter different is that the calculations ‘reflect the discovery that the widely accepted paradigm that reducing 3,500 calories will shed one pound of weight does not account for slowing of metabolism as people change their diet and physical activity, according to head researcher and creator of the Body Weight Planner, Kevin Hall, Ph.D. Hall said he created the Planner to better understand how diet and exercise contribute to weight loss. His findings were published in The Lancet Series on Obesity in August 2011.

The senior investigator at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health (NIH) said the math model for the Planner was further validated using data from a two-year calorie restriction study of 140 people. With those data, Hall and his colleagues showed the model can also provide accurate measurements of calorie intake changes by tracking people's weight.

The NIH has partnered with the U.S. Department of Agriculture (USDA) to combine the Planner with the USDA’s SuperTracker. ( The SuperTracker is a goal-setting online tool to help people achieve and stay at a healthy weight.

"We originally intended the Body Weight Planner as a research tool, but so many people wanted to use it for their own weight management that we knew we needed to adapt it with more information about how to achieve a healthy lifestyle," said Hall. "The Planner is a natural fit within the SuperTracker as it lets people accurately determine how many calories and how much exercise is needed to meet their personal weight-management goals, according to Hall.

Here’s a video of Hall showing you how the Body Weight Planner is used:

Dr. Zhaoping Li, director at the Center for Human Nutrition at UCLA’s David Geffen School of Medicine, says it’s great that the federal government is doing its part to try to help the epidemic of obesity in this country, but she said there are many other factors as to why some people burn calories much faster than others. She says food may be absorbed as three calories in a lean person and seven calories in an obese person simply because of differences in how gut bacteria breaks down the meal.

The new Planner may not make you lose weight and keep it off, but it may help the 9 out of 10 people, even dieticians, who have no real idea how many calories they’re eating in a day or how many they need to eat to lose weight. According to a survey conducted by the International Food Information Council Foundation at least 8 out of 10 people underestimate their caloric intake. The U.S. food supply produces 3,900 calories for each person per day. However all of the men surveyed claimed to eat an average of 2,618 calories daily, while women reported eating only 1,877.

When 200 dieticians calculated how many calories there were in 5 different meal plans served in restaurants, their numbers were woefully inadequate. Some of the meals even contained double the amount of calories the nutrition experts predicted.

Although you do have to weigh and measure what you’re eating, some studies have shown that it keeps you mindful of what you’re putting in your mouth and actually does help you lose weight. The good news is you don’t have to do it for the rest of your life. A week of keeping track of your meals should give you the basis to understand how many calories you’re really consuming.