“The Biggest Loser” has been a wildly popular reality TV show. Personally, I hurt for the contestants who never wanted to gain weight in the first place, and now have to put superhuman effort in to losing it. They just don’t seem to get the medical support that could increase their success and limit their pain.
Although lifestyle changes are mandatory for successful weight loss, the medical factors leading to the original weight gain in the Biggest Losers’ contestants does not seem to get the attention it deserves. Potentially, this means the weight loss is far more difficult than it needs to be and the risk of regaining the weight in the future is almost predictable.
An article in the New York Times (online 5/2/16) described the heartbreaking weight regain among the contestants…
“In fact, most of that season’s 16 contestants have regained much, if not all, the weight they lost so arduously. Some are even heavier now.”
Why would the “Biggest Losers” let that happen? After working so hard to lose weight with diet and exercise, wouldn’t they be able to subsequently keep the weight off? Apparently not! The reason has a lot to do with a slowing of the metabolism (calorie burning ability).
Research done on the contestants after weight loss revealed their resting metabolism rates had dropped far more than expected. One of the contestants, down to 295 from 430 lbs, burned 800 calories LESS per day than a normal 295 lb man who never weighed more than 295. Something about the weight loss process SLOWED the metabolism more than expected, making it ever so hard to keep the weight off.
All dieters have a similar long-term challenge after weight loss from a slowing of the metabolism. After weight loss, we burn significantly fewer calories than before losing weight AND fewer calories than prior to the original weight gain. Did you get that? Your calorie burning at 150 lbs prior to gaining to 180 lbs is significantly greater than when you diet from 180 lbs back to 150 lbs. Weight loss can make the metabolism more “sluggish”.
Indeed, weight loss creates a true “metabolism dilemma”. Our ability to burn calories after weight loss (our “metabolism rate”) slows significantly after weight loss for some very clear reasons. Let me explain:
Reason #1) Losing weight means we have become “smaller”, and a smaller person simply burns fewer calories.
Think about it. If you lose 40 lbs, your heart doesn’t have to do the work of pumping blood to those 40 lbs. They are gone! Further, your body doesn’t have to run all the chemical reactions to maintain those 40 lbs of body tissue. It is no longer necessary. Smaller people just don’t need to burn as many calories to get through the day. They need less oxygen, less blood, less perspiration, etc. Fewer calories are burned by the smaller sized body.
Reason #2) Losing weight means activity is “easier”, so fewer calories are burned with activity.
That’s right, after losing 40 lbs, it’s easier to get out of a chair, easier to go up a flight of stairs, easier to walk a mile, and easier to roll over in bed. Less work to get through the day means we are burning fewer calories with our daily activities. Less work with daily activities means calorie intake must be reduced long term to keep weight down.
Reason #3) Losing weight alters hormone levels, slowing our metabolism rate.
Ghrelin and leptin are two of those hormones. An increase in the blood level of ghrelin (a dieter’s enemy) occurs after weight loss, leading to a slower metabolism rate. And, a reduction in leptin (a dieter’s friend) in the blood also leads to a slower metabolism. These changes slow the metabolism in the body’s effort to protect us during times of famine. The blood hormones slowing the metabolism seem to remain out of balance long term after weight loss, making it ever so easy to overeat and regain lost weight. Research performed on “The Biggest Losers” TV show contestants, showed that their metabolism rates, at rest, slowed by an average of 789 calories per day (504 calories more than predicted based on weight loss alone).
Weight loss maintenance a real challenge. Let’s look at an example:
Women normally burn around 10 calories per pound. So, a 180 lb woman can eat 1800 calories per day and maintain her weight. We can estimate that 1400 calories are from the “resting” metabolism (what she would burn if she slept for 24 hours) and 400 calories are “activity metabolism” (calories due to body movement).
After weight loss, the resting metabolism rate slows 7 calories per day per lb of weight loss. After losing 40 lbs, that means burning 280 (7 x 40) calories less per day, so she is now only burning 1120 calories per day at rest.
Physical activity becomes easier after weight loss. So, walking up a flight of stairs is easier. Walking a mile is easier. Rolling over in bed is easier. Life is just easier! That means fewer calories are required for all those daily physical activities. In this example, the activity would burn about 90 calories less per day due to weighing less, so the 400 becomes 310 calories per day burned with activity.
Calorie burning is now 1120 + 310 = 1430 calories per day after 40 lbs of weight loss, compared to 1800 calories per day prior to weight loss. Instead of eating her original 1800 calories per day, she can only eat 1430 calories per day! Yikes!!! That is not much food!
And, we all tend to like eating food. So, eating less than 80% of the food we are used to long-term ends up being unpleasant to say the least!
This slowing of the metabolism (calorie burning ability) after weight loss is what I call the “Metabolism Dilemma”.
How can we keep from gaining weight after dieting?
Two factors MUST be managed long-term for success. What are they?
Weight Maintenance Factor #1: Appetite control!
Calorie intake must be reduced long term. That means suppressing appetite. For individuals who have gained more than 20-40 lbs as an adult, appetite-suppressing medications can be a true key to success. Other lifestyle appetite control strategies are always recommended as well. (See my article, “Appetite Control: The Secret Key to Permanent Weight Loss”.)
Weight Maintenance Factor #2: Metabolism management!
The same medications that suppress appetite can also increase calorie burning by having an effect on metabolism rates and an increase in spontaneous physical activity. Again, medications can be a key to success. In addition, activity is always powerful! Walking 4 miles per day, 7 days per week, is enough to increase calorie burning from 1400 to 1800 calories per day. Walking is powerful for weight maintenance. It’s why we recommend monitoring your steps every day and walking a recommend 8,000 or more steps every day (~4 miles), if possible. (For more information, see my article “Low Energy: Fixing the Power Drain”.)
Summary:
Weight gain is easy! Weight loss is hard. Weight loss maintenance is even more challenging! The “Metabolism Dilemma” must be understood and managed for long-term success. Using a combination of strategies for appetite and metabolism control is always recommended.
The medical approach to weight loss we use at the Center for Nutrition takes all the weight loss challenges in to consideration. We create individualized strategies designed to maximize weight loss success for the long term. Those same strategies often need managed and updated over time as things change. Contact us if you need assistance in losing and maintaining to a lower, healthy weight.
For Optimum Health,
Rick Tague, M.D., M.P.H.
