Tag Archives: metabolism

Lose, win, gain: The fate of Biggest Losers

The Biggest Loser has been in the news again this week. This time, though, the focus isn’t on the remarkable transformations the contestants experience through a strict low-calorie diet combined with hours of vigorous exercise each day.  The results are impressive considering that the average weight loss of the winners is almost 170 pounds, or nearly 50% of their original weight! The show does demonstrate that hard work and dedication do lead to results, and provides inspiration for many viewers who should lose weight themselves.

But what happens when the cameras are turned off? Unfortunately, most of the contestants regain much of the weight they lost during the show and some end up even heavier than they were at the beginning. A new study published last week confirms that this is true and suggests that long-lasting changes to metabolic rate are to blame. But there is more to the story, which is relevant to anyone who has lost weight and gained it back, as I explain in my Health & Fitness Column in the Aiken Standard this week.

feet on scale


The new study followed contestants from season 8 of the Biggest Loser for six years. Only one of the 14 contestants continued to lose weight after the show ended. The others gained back much of the weight they lost and four are heavier than they were previously. The researchers also measured resting metabolic rate which tells how many calories you burn at rest, the majority of your energy expenditure each day. The results show that the metabolic rate of the contestants decreased significantly after the show ended and stayed low for years. The decreased metabolic rate was expected, but the fact that it stayed low for so long was a surprise.

This finding is an important reason why the contestants gained weight back: they were burning hundreds of calories less each day! Considering that a difference as small as 100 calories per day can lead to weight gain over time, it is no surprise the Biggest Losers became big gainers. Even if they were careful to maintain a low calorie diet and exercise every day, weight regain was almost inevitable.  This change was so dramatic because of the extreme weight loss; people who lose more reasonable amounts of weight would have a much smaller change in their metabolism.

While the change in metabolic rate is important in explaining weight regain in Biggest Loser contestants, it is far from the only factor. In order to lose weight and keep it off, people need to learn a whole new lifestyle involving what, when, why, and how to eat and exercise. These lifestyle changes are difficult to make and can take months or years to fully adopt. Participating in any weight loss competition, whether that is the Biggest Loser or a team weight loss program at work, leads to quickly losing weight by following and inappropriate diet or participating in exercise that is too intense instead of learning new skills and behaviors.  Again, maintaining that weight loss is difficult, to say the least.

It shouldn’t come as a surprise that losing weight rapidly, especially under the watchful eyes of doctors, nutritionists, and personal trainers (not to mention millions of viewers), would be difficult to sustain upon returning home without that support. This is consistent with prevailing wisdom that the quicker someone loses weight, the quicker they are likely to gain it back.

The lesson here is that there are powerful biological changes that occur following significant weight loss that make it challenging to keep the weight off. Add to that a focus on losing weight quickly rather than developing long lasting habits only makes it more difficult.  Being a “successful loser” requires realizing that the effort must be sustained long after the diet ends.


Nutrition, exercise, and health information can be confusing. 
But it doesn't have to be that way.
What can I help you with?
 drbrianparr@gmail.com | http://twitter.com/drbrianparr

Despite the controversy, energy balance still matters.

The concept of energy balance has been in the news again this past week. Unfortunately, the media reports focused on controversial funding for a network of researchers, not on practical information that could help people with weight control. In my Health & Fitness column in the Aiken Standard this week I take the opportunity to explain what energy balance means and, despite the controversy, how it can help you achieve and maintain a healthy body weight.

walking weight loss


First, it is worth explaining what energy balance means. Basically, the energy balance model suggests that your body weight is determined by the balance between the number of calories you consume and the number of calories you expend each day. It is often illustrated as “calories in, calories out” and is the basis for the most basic weight loss advice: eat less and move more.

Now for the controversy. It was recently reported that the Global Energy Balance Network (GEBN), an organization aimed at promoting activity and health, received money from Coca-Cola, a company that promotes the consumption of sugar-sweetened beverages.  Furthermore, the obesity and exercise researchers at GEBN started focusing more on the lack of activity, instead of unhealthy food, as a major cause of obesity. Whether this is truly a real conflict of interest or simply a reality of funding a non-profit health organization remains to be seen.

It is important to note that this doesn’t mean that the efforts of GEBN scientists or the concept of energy balance in general should be dismissed. In fact, the energy balance model is a simple and effective way to explain how weight gain and weight loss occur. In fact, the only treatments we have for obesity focus on changing energy intake and energy expenditure. While some suggest that the “calories in, calories out” idea is too simplistic, it certainly helps people understand why they have gained weight and provides an intuitive guide to losing weight. This is most commonly expressed as “eat less, move more” and is the foundation of nearly every effective weight loss program.

For most researchers, practitioners, and people in general, the focus is typically on the “energy in” and “eat less” parts of the equation. Nearly all diets work by reducing the number of calories someone eats, even if they claim that you can eat as much as you want. Common recommendations to cut back on sugar or fat tend to lead to eating fewer calories, especially if those foods are replaced by fruits, vegetables, whole grains, and lean meats. Since we now know that eating fat won’t necessarily make you fat, the emphasis has shifted to sugar as a cause of weight gain. And sugar-sweetened beverages, including soda, are a major source of sugar for many people, especially children. So, most experts recommend consuming less soda, candy, and other sources of added sugar.

But there is another part of the energy balance model that can’t be ignored—energy expenditure. One goal of the GEBN is to emphasize the importance of activity in achieving energy balance and a healthy body weight. The focus on physical activity makes sense considering that the component of energy expenditure you can control is your activity level. This includes exercise, other occupational and leisure activity, and limiting sedentary (sitting) time, with a goal to be as active as possible throughout the day. The key is to achieve a balance between what you eat and drink and the energy you expend by being active.

The importance of exercise and energy expenditure for weight loss is shown by the members of the National Weight Control Registry, commonly called the “successful losers” because they have lost an average of over 50 lbs and kept it off for over five years. They lost weight by following a variety of diets and programs but nearly all continue to exercise regularly. This suggests that physical activity to promote “energy out” is at least as important as diet when it comes to maintaining weight loss.

In fact, if energy expenditure is high enough, a person could get away with eating almost anything he or she wants. In the 2008 Olympics, swimmer Michael Phelps famously revealed what he ate on a typically day. The amount and type of foods he consumed were not what you would expect from someone so fit and healthy! Without the hours of training he engaged in each day that diet would almost certainly have resulted in obesity and poor health.

Clearly, increasing physical activity is important both for weight control and health in general. But diet matters, too. And while the energy balance model says that there is nothing wrong with having your favorite foods or drinks as long as you are active, most of us could benefit from drinking less soda and moving a bit more. In this way, keeping yourself in energy balance should allow you to maintain a healthy weight without depriving yourself too much. The key is, and always has been, to find a balance between what you eat and drink and the energy you expend by being active.


Nutrition, exercise, and health information can be confusing. 
But it doesn't have to be that way.
What can I help you with?
 drbrianparr@gmail.com | http://twitter.com/drbrianparr

Your metabolism (and how to speed it up)

Many people are interested in speeding up their metabolism in an effort to lose weight. There are drugs, supplements, and even certain foods that are thought to increase metabolism. The effectiveness of many of these things is unproven and some may actually be dangerous. The goal of this article is to explain what the term “metabolism” really means and how it can be changed.

Metabolism refers all of your body’s processes that expend energy, or burn calories. Practically, this is how much carbohydrate, fat, and protein is burned throughout the day to provide energy for your cells. If you expend more energy than you consume in your diet, you will lose weight.

The amount of energy you expend in a day is composed of three main components: your resting metabolic rate (RMR), something called the thermic effect of food (TEF), and the energy you expend in activity.

Resting metabolic rate (RMR) is sometimes called the basal metabolic rate (BMR), but many people refer to it as their “metabolism.” No matter which name is used, it refers to the calories you burn at rest. It represents the energy needed to maintain your essential body functions: heart rate, breathing, body temperature, and normal cellular processes.

The RMR is important because it represents about 60–70% of the total calories a typical person burns in a typical day. Even though RMR is important, you shouldn’t worry about it too much.

First, it is difficult to change. RMR is based mostly on your lean body mass, so the only way to increase it is to gain muscle mass. While this is a good goal, it is challenging to do, especially while you trying to losing weight.

Second, although it does vary among people, it isn’t as different as people like to think. It is easy to think that someone who gains weight has a “slow metabolism” or that someone who is thin must have a “fast metabolism.” In reality, the RMR probably isn’t much different, certainly when you take lean body mass into account. The explanation for the differences in weight among people probably has more to do with what they eat and how active they are.

The thermic effect of food (TEF) represents the energy needed to digest, absorb, and store the nutrients you eat. It accounts for only about 10% of your total energy expenditure and it is practically impossible to change, so you can ignore it.

Activity is the most variable component of energy expenditure and the one you can most readily change. Obviously, it will vary based on how active you are, but for most people it accounts for 20–30% of total energy expenditure.

Activity includes both purposeful movement such as exercise and doing work or tasks that require you to move. Activity also includes non-exercise activity thermogenesis or NEAT, the calories you burn when you move around, but not in a purposeful way. Maintaining your posture when sitting or standing, fidgeting in your chair, or other light movements count as NEAT.

The surest way for you to increase your metabolism is to limit the time you spend sitting, be active as possible at all times, and dedicate time to exercise every day. Doing prolonged aerobic exercise such as walking, jogging, or exercise classes directly burns calories and including strength training will help increase your muscle mass, which can increase up your RMR.

The bottom line is that speeding up your metabolism requires you to move. So, get up off the couch and go for a walk!

Funny calorie math.

Have you ever heard that a few extra calories each day—an extra soda, for example—can add up to significant weight gain over time? Or that making small changes in what you eat, such as skipping dessert, can promote weight loss? If so, you are familiar with the concept of energy balance. And if you were ever surprised by those claims, you are familiar with what I call funny calorie math.

This is the topic of my Health & Fitness column in the Aiken Standard this week.

Your body weight at any time is determined by the balance between the energy you take in and the energy you expend. The “energy in” part is simple, it’s the calories in the food you eat.

Your energy expenditure is determined by your basal metabolic rate (BMR), the calories burned keeping you warm and alive, as well as the energy you expend in activity. Of these, the BMR accounts for the majority of your energy expenditure, but you have the most control over your level of activity.

According to this energy balance model, eating or drinking an additional 250 calories per day would add up to about one pound of weight gain every two weeks and 26 pounds after one year (using the rough estimate that to gain a pound requires 3500 extra calories.

+250 calories/day  x  7 days/week  =  1750 calories/week  =  3500 calories/2 weeks

3500 calories/2 weeks  x  1 lb. weight gain/3500 calories  =  1 lb. weight gain every two weeks  =  26 lbs. weight gain per year!

Calculations like this are common, typically used to point out how fattening a particular food or beverage can be. But the same principle can be applied in reverse to determine weight loss.

Example: Eat (or drink) and extra 250 calories per day

250 calories/day  x  7 days/week  =  1750 calories/week  =  3500 calories/2 weeks

3500 calories/2 weeks  x  1 lb. weight loss/3500 calories  =  1 lb. weight loss every two weeks  =  26 lbs. weight loss per year!

The same formula predicts that cutting back by 250 calories per day should lead to losing 26 pounds in one year. This idea is the basis for suggesting that making small changes to your diet can lead to significant weight loss over time.

You can do the same thing with physical activity, too. Adding a 45-minute walk, which burns approximately 250 calories, each day should lead to the same 26 pounds of weight loss in a year.

Example: walk 2.5 miles in 45 minutes each day, using the rough estimate that you will burn 100 calories per mile.

2.5 miles/day  x  100 calories/mile  =  250 calories/day

250 calories/day  x  7 days/week  =  1750 calories/week  =  3500 calories/2 weeks

3500 calories/2 weeks  x  1 lb. weight loss/3500 calories  =  1 lb. weight loss every two weeks  =  26 lbs. weight loss per year!

The assumption, of course, is that you aren’t changing anything else as you eat 250 fewer calories or burn an additional 250 calories per day through exercise. It would be relatively easy to offset the energy expended though a walk by even a small change in what you eat. This is the biggest weakness of this energy balance model—in order for it to accurately predict weight loss or gain, nothing else can change.

Unfortunately, this isn’t the way it really works. Changes in body weight through eating or exercise also lead to changes in total energy expenditure. As you lose weight, the total calories you burn in a day drops, mostly due to a decrease in BMR, since it is based on your body weight. The result is that over time you don’t lose weight as quickly. The exact opposite occurs with weight gain, which causes BMR to go up, limiting weight gain.

This leads to a different outcome: the extra 250 calories per day is likely to lead to a weight gain of closer to 10 pounds (maybe less) due to your BMR increasing as you gain weight over the year. And the estimation of weight loss will be different, too, given that BMR will drop slightly over time.

This is one of many reasons why exercise is important for weight loss. You can offset the lower BMR that occurs as you lose weight by increasing energy expenditure through activity. Additionally, regular exercise can add to the weight you lose through a diet and help keep the weight off later.