September 3, 2012 in Features

Rock Doc: Hitting below the belt

E. Kirsten Peters
 

If you’ve recently made a resolution to eat right and trim down, be forewarned that your brain has it in for you and will actively promote your failure on two different fronts. That’s not good news, of course, but you should know about it so you can strengthen your resolve. I wrote about all this not long ago, but the message bears repeating, particularly since so many of us face the battle of the bulge.

Here’s the scoop. It’s relatively easy – particularly if you are significantly overweight – to lose a few pounds by reducing the number of calories you consume each day.

The problem is that your initial success will trigger a couple of responses in your body. First, as you lose weight a hormone called leptin – which is produced by your fat cells – will start to drop in concentration. That change tells your brain that your stores of fat are decreasing. The brain responds to that report as if famine is on the way. The body makes changes to conserve its energies, and your metabolism will drop.

Metabolism – the rate at which we burn energy – is a major key to what our weight tends to be. The lower your metabolism, the easier it is to consume more calories than you burn in a day – triggering weight gain.

Here’s how that works in practice. Imagine you weigh 175 pounds for a number of years, but then your weight creeps up to 200 pounds. You go on a diet and successfully get back to 175. Congrats! But your metabolism is likely to now be slower. That means you have to eat fewer calories to maintain yourself at 175 after weight loss than you would have if you had always weighed that amount.

But the scientific news gets worse.

At your post-diet weight of 175, there’s a double whammy. Simply put, you’ll likely feel plenty hungry after your weight loss. The reason is that some other brain chemicals will be triggered that tell you that you feel peckish. So on the one hand you’ll need fewer calories than someone of your weight who has never dieted, while at the same time you’ll feel hungrier than someone who has always been trim.

I’m afraid it’s the boring old advice that’s most useful if you are serious about trimming down. The best chance of success you have is to modify your diet toward eating right in a way you can do for the rest of your natural life. “Dieting” shouldn’t be about short-term weight loss based on serious deprivation – you need to find what works for you that you can sustain over the long term.

Another key to success is exercise. General medical advice is to get 30 minutes per day of moderate exercise. But to maintain weight loss, you’ll likely have to do better. Many advisers in medical science say a person needs to do an hour of exercise each day to keep off pounds shed through dieting.

Nothing about weight management is easy. But some people are successful in trimming down and keeping off the weight. Let’s keep them as models for our own efforts and encourage one another to take on the challenging but rewarding work of helping our health through diet and exercise.

E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. Send questions to her for future Rock Doc columns at epeters@wsu.edu. This column is a service of the College of Agricultural, Human and Natural Resource Sciences at Washington State University.


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