Coke has a new online ad, beautiful, happy, clever, and logically twisted.
The ad (see below) imagines what would happen if people paid for their can of Coke by working off the calories it contains. It shows that people are different, but on average, working off a can of soda takes just 23 minutes of cycling.
In this imaginary world, soda makes thin people exercise -- and imaginary worlds are a nice respite. But it also distorts human physiology on many levels.
You don't really burn 140 extra calories in 23 minutes
The time it takes the riders to burn their 140 calories varies and depends on the speed of their pedaling and their weight (the heavier and larger a person is, the more they burn). These of course are just estimates -- calorie trackers don't really measure the calories you burn.
But the important thing to remember is that that estimate on the treadmill or the bike's display is for the total you burned during those 23 minutes, not for what you burned extra during the exercise session. If you were sitting at your computer, you'd burn 40 calories during that time. If you were shopping, you'd expend about 54 calories. The amount of extra calories you burn, what you really "earned," is the number of calories you exerted minus what you would have spent on an ordinary day, and we burn quite a few calories even in our sleep (50 per hour). In the best case scenario, I'd say those 23 minutes of biking add to the daily expenditure tally just 60-100 calories, and that's if you're careful not to compensate by a little more couch time that day -- and you'll really have to be careful, as our body aspires to a steady state and resists changes in energy.
140 calories aren't the problem, soda is
Let's put numbers in context: 140 calories are just 7 percent of the daily caloric allowance for an average person. A large banana has as many calories as can of soda, and a handful of nuts have more, and most health experts highly recommend you do eat those. Soda isn't on the "don't" list because it's a calorie bomb, but because its calories are entirely empty. One can of soda has more sugar than what we should consume in an entire day. And there is something unique about liquid calories, as they don't count towards satiety; we're therefore advised to cut these specific calories to a minimum.
Soda is linked to obesity and disease not because it's the most calorically-dense food of them all -- it isn't -- but because these are added-sugar calories that are conducive to overconsumption and poor metabolic health.
Exercise won't solve obesity
Most people will not lose weight when they start an exercise program. To lose weight they'll need to also watch what they eat, i.e., eat less.
Researchers have puzzled over why this is the case, and I won't go into it right now, but at this point it's clear: There's no way ordinary people whose day jobs don't involve physical labor can exercise to the level in which they could eat as much as the food industry suggests they do.
We need to be active for our health and well being, not so that we'll be rewarded with eat-less-of food. Exercising for a sweet reward usually leads to weight gain, because we tend to overestimate caloric expenditure, and underestimate intake.
The math just doesn't work, and neither does the myth. Exercise will not solve our obesity crisis, nor will it allow us to eat whatever we wish.
Full disclosure: I'm vice president of product development for Herbal Water, where we make organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I'm also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years. On top of that, I really enjoy Coke ads, and wish the talent behind them would be used to further health.