The “10-20” Rule and the Ice Water Diet. June 21, 2011.

This excerpt comes from Dr. Brian Wansink’s book Mindless Eating:  Why We Eat More Than We Think.  Wansink writes:

“In every beverage study we conduct, people underestimate the calories they drink – usually by about 30 percent. It doesn’t matter whether it’s soft drinks, milk, juice, or wine, although fountain machines pose the biggest danger.

My lab developed a ’10-20′ rule of thumb for teaching people to estimate the number of calories in a drink. ‘Thin drinks’ (like soft drinks, punch, juice and milk) are about 10 calories per ounce and ‘thick drinks’ (smoothies and meal replacement shakes) are about 20 calories per ounce. It’s ballpark, but it’s better than mindless drinking. Just poured a 32-ounce Coke at McDonald’s? Think 320 calories, including ice.

Interestingly, if you load that drink with ice, you’ll actually burn off a few of those calories. Since your body has to use energy to heat up an iced beverage, you actually burn about one calorie for every ice-cold ounce you drink. So that 32-ounce drink will take you 35 calories to warm up.

No big deal? If you drink the recommended eight 8-ounce glasses of water a day, and if you fill those 64 ounces with ice, you’ll burn an extra 70 calories a day” (Wansink, 189).