Tuesday, April 27, 2010

Will posting calories help control obesity?

The one thing in Obama’s healthcare bill that I have been supportive of is the requirement that restaurants post calorie information on menu’s. Panera Bread cafés began doing this recently of their own initiative. Does it work?

My wife and I ate in Panera for dinner last night. Based on the calories posted I chose a half Cuban chicken sandwich and half cobb salad. 680 calories was within my 900 calorie dinner allowance. So far so good. They also have a promotion for a bakery item for 99 cents. That 490 calorie orange scone (my future daughter-in-law makes real (and very good) scones, Panera’s are not real but more like scone shaped muffins) sure was good.

Based on this study, posting calories is of little benefit 

FitBit

While we’re talking about calories… I read an article recently about a device called a fitbit. It measures your activity throughout the day and tells you how many calories you’ve burned. Sounds like a good thing.

This morning I heard a group of POS (persons of size) talking about something similar that they all have. They were all excited because their devices showed that they burned 250 calories going on a 40 minute walk. “I can eat a candybar.” one said.

There’s a danger in this. Thanks to our metabolism we naturally burn a bunch of calories throughout the day, usually between about 1500 and 2500. I burn about 60 calories per hour when I’m sleeping, about 80/hr for the approximately 12 hours I’m fairly sedentary sitting at my desk, and about 190/hr for the 4 hours I’m somewhat active which includes things like taking a shower, grocery shopping, or cutting the grass. For all of this I can eat about 2200 calories a day and not gain weight. Eating anything more than my base metabolic rate will destroy my svelte figure.

If, for one of my ‘active’ hours, I go for a long walk that burns 250 calories, I haven’t burned an extra 250, but only an extra 60 or so. I’d actually have to walk a 250 calorie per hour pace for a bit over 4 hours to burn off that candybar. I do a lot of bike riding and burn about 1000 calories per hour (approx 20mph pace). That doesn’t mean that I can eat an extra 1000 calories though. Realistically I’ve only burned about an extra 800 calories. In reality though I find that for that 1000 calorie ride I can only eat about 600 calories over my 2200 calorie metabolic rate or similarly 1200 calories on a day I’ve supposedly burned 2000 calories on my bike. I’m not sure if my computer and various charts give high calorie burn information or if it just takes more than a calorie to burn a calorie.

Moral of the story – be careful how many calories you think you’ve burned.

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