A new simulation model predicts weight changes with varying diets and exercise plans.  Researchers at the National Institutes of Health (NIH) have created a mathematical model — and an accompanying online weight simulation tool — of what happens when people of varying weights, diets and exercise habits try to change their weight. The findings challenge the commonly held belief that eating 3,500 fewer calories — or burning them off exercising — will always result in a pound of weight loss.

Instead, the researchers’ computer simulations indicate that this assumption overestimates weight loss because it fails to account for how metabolism changes. The computer simulations show how these metabolic changes can significantly differ among people. Findings are published Aug. 26 in a Lancet issue devoted to obesity.

However, the computer simulation of metabolism is meant as a research tool and not as a weight-loss guide for the public. The computer program can run simulations for changes in calories or exercise that would never be recommended for healthy weight loss. The researchers hope to use the knowledge gained from developing the model and from clinical trials in people to refine the tool for everyone.

“This research helps us understand why one person may lose weight faster or slower than another, even when they eat the same diet and do the same exercise,” said Kevin Hall, Ph.D., an obesity researcher and physicist at the NIH, National Institute of Diabetes and Digestive and Kidney Disorders (NIDDK)  and the paper’s first author. “Our computer simulations can then be used to help design personalized weight management programs to address individual needs and goals.”

The online simulation tool based on the model enables researchers to accurately predict how body weight will change and how long it will likely take to reach weight goals based on a starting weight and estimated physical activity. The tool simulates how factors such as diet and exercise can alter metabolism over time and thereby lead to changes of weight and body fat.

To test the model, the researchers compared predicted weight changes to actual changes in people. For example, the team found that people’s bodies adapt slowly to changes in dietary intake. They also found heavier people can expect greater weight change with the same change in diet, though reaching a stable body weight will take them longer than people with less fat.

The model also points to a potential simplified method to approximate weight loss in an average overweight person. An adult who has a body mass index (a measure of a person’s weight in relation to his or her height) between 25 and 29.9 is considered overweight. One example: For every pound you want to lose, permanently cut 10 calories from your current intake per day. At that rate, it will take about one year to achieve half of the total weight loss, and almost all of the weight loss will have occurred by three years. This calculation shows how long it takes to achieve a weight-loss goal for a single permanent change of diet or exercise. Researchers can use the web simulation tool to plan for a phase of more-rapid weight loss followed by a weight maintenance phase. People should consult with their physician prior to embarking on a diet plan.

“This research illustrates how the interdisciplinary skills of NIH scientists, like a physicist doing obesity research, can help lead to innovative ways to test, understand and treat a major public health epidemic,” said NIDDK Director Griffin P. Rodgers, M.D. “Advancing research from the laboratory to the bedside enables us to make the discoveries that can better people’s lives.”

 

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Comments

I beleive this research helped to understand why one may lose weight faster or slower than another. All this computer simulations are very good way of research.

Im Sure a person's thyroid might play a roll in this also any thoughts?

I often wondered why one person can loose weight easier than another, I had to read this blog a couple of times to get it, I have downloaded the tool it looks very interesting

Let's hope that some day this research can result in a weight loss aid of some sort, rather than remain just a rather interesting Ivy Tower experiment.

Different people have different conditions. One person may be able to lose 2 pounds per week while other may only able to lose 1 pounds in one month. It's great tool to calculate how much one person can lose weight based on metabolic level. But the question is how accurate the tool can become since there are more factors affecting your weight more than just metabolic level (health-related problems, hormone, stress level, psychological issue, lifestyle, climate, geography and so on)

New research often disproves previously held doctrine and sometimes helps dispel commonly held beliefs. With weight loss/gain or most any other medical condition for that matter a "one size fits all" arbitrary generalization is fatally flawed. Smoking kills and causes numerous diseases yet we find people who have smoked all their adult life living well beyond 80 or 90. Likewise a sedentary lifestyle (ie little or no exercise) coupled with too much junk food supposedly causes obesity, yet if we look around workplaces we find people in all shapes and sizes from skinny to obese. Undoubtedly unhealthy lifestyle choices are contributing factors but individual metabolism and other characteristics must also be taken into account.

This was a very interesting read! Lots of opinion and very good research to be shared! Good feedback from the online readers as well. I must commend the author and web designer as well. Thank you for taking the time to share this with us.

Yes, I have found that my husband can lose weight easier than I can. I would consider myself an average weight for my age and height but it still becomes discouraging that it is easier for others to lose weight. It is a lifetime change and I that is an interesting point about permanently cutting out 10 calories a day. Thanks for posting.

"The researchers hope to use the knowledge gained from developing the model and from clinical trials in people to refine the tool for everyone." - I look forward to the trials being complete so we can see this on the market place

It still becomes discouraging that it is easier for others to lose weight. It is a lifetime change and I think it is an interesting point about permanently cutting out 10 calories a day. Thanks for posting.

Metabolic rate plays a big part when it comes to weight loss. It was so much easier losing weight 10 years ago as opposed to now when i'm in my 30s.

What Dave has mentioned above is correct. There are a lot of tools in the market that stayed on the shelves and did not add value to dieters. My advice to anyone who is looking to lose weight is not to wait for any tools. Just start your exercise and watch your calorie intake. Getting started is all what it takes. Job begun half done.

I’m wondering how I would react if I went to a restaurant and they brought me a plate of colourless food. Would eat it? Yes. But would I enjoy it? I’m not quite sure. The damage has been done, I’m already conditioned to enjoy food with colour…

I cannot leave your site. I keep finding interesting blogs to read. As you exercise more, your metabolic rate rises, even at rest, which burns more calories. I think this info paired with a nutritionist and trainer should be a recipe for success.

Good blog! I've learned some things with this article! I found out i'm obese. :S

I always believe that people have different ways of reacting to habits and exercise habits. I've followed the assumptions in the past and my weight didn't turn out well as I expected. Hopefully, this customized exercise regimens and diet will help me to lose desired weight before I lose my mind over weight.

I would recommend the mediterranean diet because includes all kind of nutrients. Regards!

Good article! From own experience I found that counting calories all day can be exhausting and somewhat demotivating. So I decided to try to pre cook my meals leaving me without the worries about counting calories all day long, and the meal size would be about 1½ of your fists size, with a ratio of 40% proteins, 30% vegetables and 30% carbs. - Marc

I always believe that people have different ways of reacting to habits and exercise habits. I’ve followed the assumptions in the past and my weight didn’t turn out well as I expected. Hopefully, this customized exercise regimens and diet will help me to lose desired weight before I lose my mind over weight.