fit info

For the past 2 weeks, we looked at the Fallacies:
"The amount of bodyfat you carry affects your metabolism"

Metabolism 101, part 1


"Most People who are overweight have slow metabolisms"

Metabolism 101, part 2

"Most People who struggle witih their weight are likely suffering from a thyroid disorder"

Metabolism 101, part 3

"When you hit a Sticking Point during Weight Loss, it's due to a Stalled Metabolism"

Metabolism 101, part 4

May 27, 2007

"Hitting a weight-loss Plateau?" Metabolism 101, part 3

FOUR THINGS YOU PROBABLY DIDN'T KNOW ABOUT YOUR METABOLISM-BUT SHOULD, IF LOSING FAT AND STAYING LEAN IS YOUR GOAL

This is an article By Carey Rosse, from muscleandfitnesshers.com. For the past several weeks, we have been presenting a different Fallacies and Facts about Metabolism from this article .

Fallacy: "When you hit a Sticking Point during Weight Loss, it's due to a Stalled Metabolism"

Fact: Plateaus are a sign that your metabolism is doing its job

When trying to lose weight, most of us have hit the dreaded sticking point-when the scale won't budge, your clothes aren't getting looser and frustrations begin to rise. It's the perfect time to re-evaluate your eating and exercise plan, and consider: How much weight have you lost so far?

"As most people find out, they can lose 10% of their body weight before it becomes more difficult to lose another 10%," says Robert Keith, PhD, RD. FACSM, professor of nutrition and food science at Auburn University (Auburn, Alabama)." At about that point, the weight won't come off as fast as it once did."

There are two reasons why: First, you're smaller, so your metabolism is matching the "new" you. Second, your body thinks it's starving, and as a result, thyroid hormone levels drop and our resting metabolic rate may drop 10%-20%, so you aren't burning as many calories in a day as you were. And here's what most of us forget: when we lose weight, we become lighter, meaning the amount of calories we burn in everyday activities drops as well. Eventually your metabolism adjusts to your new, smaller body.

"At some point you come back to energy balance-where your ouput and input are the same, so you stop losing weight, " Keith explains. "Thats the sticking point or plateau a lot of people talk about."

If losing more weight is your goal, you'll have to either exercise more or restrict your calories more, but be wary, if you're already at a healthy weight, be honest with yourself in analyzing whether you truly need to push to lose even more. There's no viable reason to take your weight loss to the extreme.

Among all these fallacies, there is one truth we've all heard before: As we age, our metabolisms do slow down. "Typically, we use a number like 20%-25% to describe how much your metabolism decreases from the time you're 22 to the time you're 75 or so," Keith explains. So if you had a RMR of 1,500 calories at age 20 then at age 75 your RMR may be 1,200 calories.

Part of the decline in metabolic rate is hormonal. "Your hormones aren't as geared up as they once were when you were younger, " notes Keith. But if you're able to preserve your muscle mass, that will help offset the drop somewhat. And remember, fat-free mass is the greatest predictor of metabolic rate. Since you're reading MUSCLE & FITNESS HERS, you probably put in some time in the weight room, and your efforts won't go metabolically unnoticed.

All in all, it can be said that metabolism is the great equalizer. The body likes to defend its weight. "If you eat too much and gain weight, your metabolism goes up trying to fight this weight gain," David C. Nieman, PhD, FACSM, director of the Human Performance Laboratory at Appalachian State University (Boone, North Carolina) says. "If you eat too little, the metabolism slows down below normal to help the body conserve what it has so it doesn't lose as much as expected."

"Your body is going to make adjustments to protect itself," adds Keith. "At some point you come back to what we call energy equilibrium; energy intake is equal to your energy output-and you stop losing weight." Ultimately, the metabolism wants to maintain balance and, in the grand scheme of things, that's a function that actually makes a lot of sense.

Metabolism 101, part 1

Metabolism 101, part 2

Metabolism 101, part 3


Past SWAC Fitness Info Articles