While reading Fran’s fitness blog, I started to think about why counting calories doesn’t work as well as it should. Even with a diet diary, tracking calories, carbohydrates, fats, and fibre is not as scientific as it should be. One problem is the serving sizes on the label don’t necessarily correspond to what we actually eat. For example, my breakfast cereal serving size is “1 cup cereal with 1/2 cup skim milk.” Like almost everyone else, I don’t measure, I just fill up the bowl. Today, I measured and found I was using 1 1/4 C cereal and 10 oz (versus 4 oz) of milk. The 1/4 C extra cereal is 47 calories. The extra milk, 90 calories. Those 137 extra calories could add an extra 14 pounds per year:
137 calories/day * 365 days / 3500 calories/pound = 14.3 pounds
1 pound fat * 453.6 grams/pound * 9 calories/gram fat = 4082 calories
10% of the fat content is water: 0.9 * 4082 = 3,674 calories
5% of this “passes through”: 0.95 * 3,674 calories = 3,490 calories.
For ease of math, we’ll round it to 3,500 calories.
Apparently this is pretty common. According to the Washington Post (Lean Plate Club by Sally Squires, free Registration Required), studies show people understimate what they eat by 40%.
We all know weight loss occurs when there’s a caloric deficit, while weight gain occurs when there is a surplus. The formula is simple:
Suppose there’s a relatively sedentary male acquaintance of ours. We’ll call him
Dude likes easy math, so today, Dude is 5′ 10″, and 240 pounds, making his basal metabolic rate (BMR), the amount of food necessary to maintain normal body function and steady weight, 2,000 calories a day.
Let’s assume Dude wants to lose 20 pounds.
For the first calculation, Dude wants to lose weight without exercising and latches onto the Starvation Diet, which apparently involves sewing your lips shut. With a 2,000 calorie-a-day deficit, it would take Dude about 35 days to drop those 20 pounds:
20 lbs * 3,500 calories / lb = 70,000 calories
70,000 calories / 2,000 calories/day = 35 days
35 days. Well, Dude, it’s probably worse. First, the BMR would decrease as Dude loses weight. (For example, at 220 lbs, the BMR is 1,938 calories.) Second, this dude’s body would go into survival mode, and start reducing body function, further decreasing the BMR. Finally, we’ve ignored the boomerang effect that would occur when Dude goes off the diet.
For the second calculation, suppose Dude just can’t give up his Cream Cheese Brownies. He insists on keeping his 2,000 calorie diet the same, but he promises to exercise it off. Here are some of his options:
- Bowling — it’s not the most taxing sport, however. For example, one game consumes about 50 calories. Dude has to bowl 1,400 games! During this time, one of his arms becomes noticably larger than the other.
- Ride a bike — if Dude rode a bike at 12mph, he could expect to burn 871 calories an hour. Better, but it would still take 80 hours of non-stop cycling, without eating, to lose 20 pounds. Not eating is going to be a serious problem since
the body stores about 2,000 calories in glycogen. In theory, Dude can bike at a slow enough rate such that he’s burning mostly fat for calories, but this just increases the time in the saddle. (For comparison, during 7 1/2 hours of biking Flying Wheels, I burned about 5k calories, but I consumed at least 3,500 calories in the process.)
- Running — let’s suppose Dude runs a marathon at a 10-minute mile pace, or 1,089 calories an hour. Over the course of the marathon, he’d burn up 4,755 calories. 15 marathons ought to do it…. except the very few people who can bang out 15 marathons aren’t the same ones who have to lose 20 lbs. (Dude will still have the same glycogen limitation with cycling.)
These examples are deliberate: reducing eating helps, exercise helps, but neither will work as well on its own. I suppose that it is for this reason eBay is so profitable as people seek a quick fix.
If you go to eBay’s home page, you’ll notice that at any given time, their “featured auctions” include at least one “Lose 95 lbs” auction. I just checked, and there are three. eBay makes a lot of money off these high-churn, snake-oil salescreatures. It rewards them with metallic Power Seller status and a special icon that implicitly conveys some kind of credibility.
Thing is, all these auctions read the same (see buff female,
pumped male). The ingredients are all claimed to be safe, effective, cheap, delivered quick shipping, etc; the implied human testimonials shown have not only lost weight, but they are also tanned, their vision has mysteriously improved such that they no longer need glasses, boobs/pecs are more pendulous, abdomens have the “six pack” look, and butts are tighter. Because these are obviously amazing pills, the auctioneer has typically hit the 1,000 “feedback” mark. If you actually read the “feedback,” you’ll notice that it is based primarily on the auctioner’s ability to place the pills in the mail and have them arrive. Efficiacy is rarely mentioned.
For the third calculation, Dude goes on the Deluxe eBay All-star Diet (D.E.A.D.). He buys these magic
sugar pills, but doesn’t modify his diet or exercise habits.
The fine print of these ads suggests 12 pounds a week is a typical amount of weight loss. To put this in perspective, this is saying that Dude, on a 2,000 calorie diet, is effectively consuming minus 42,000 calories during that period. The pills defy physiological logic by creating minus 56,000 calories:
The basic truth: Weight loss (lbs) = (calories burned – calories consumed) / 3500 Rearranging the equation: Calories Burned – Calories Consumed = Weight loss (lbs)* 3500 Calories Burned – Calories Consumed = 12 pounds * 3,500 calories / pound Calories Burned = 42,000 + Calories Consumed = 42,000 + 2,000 calories/day * 7 days = 42,000 + 14,000 = 56,000 calories
Think about it for a moment. The claim is that the pills negate the 2,000 calories Dude consumes and speed up Dude’s metabolism 3x. Without any side effects. Conclusion: the pills cannot possibly work. Most likely: Dude would be out at least $14, is slightly dehydrated from extra water loss, and has already left his eBay feedback for “quick shipping.” He’s also too embarrassed to admit he’s such a doofus for believing the advertisement, or he’s afraid of retributive negative feedback. The worst case is the pills do something irreparable to Dude’s body like shutting down his renal function, destroying his liver, or giving him a heart attack. (Death is guaranteed easy weight loss.)
What should Dude do? Make a permanent life change to eat less, exercise more, and skip the pills. If Dude can create a relative deficit of 600 calories a day, he’ll lose 15-20 pounds in about six months. Here’s how he might create that deficit:
Eating less: Dude can cut out 180 calories by drinking one fewer sugared soda a day. (Dude, try plain carbonated water. Just don’t substitute a venti Starbucks Mocha with whipped cream — that will add 490 calories.) If Dude switches from Whole milk to 1%, he’ll save another 50 calories. For good measure, Dude also passes on the french fries, opting for a fruit salad.
Exercise: If Dude walks his dog for an hour, he’ll consume 375 calories.
Another suggestion is to maintain a diet diary. Even though it’s hard to accurately measure portions and correlate them to calories, fat, carbos and fibre, the mere act of writing things down every time you eat will provide useful insight. In my case, it was useful to see how often I snack: a handful of tortilla chips here, ten chocolate chips there, some crackers — it all adds up.
There are also support groups such as Weight Watchers who have had a good track record of success. One of the most graphic examples I’ve seen was a woman who showed a group what one pound of fat physically looked like.
Two columnists I can recommend are The Wall Street Journal’s Tara Parker-Pope, and the Washington Post’s Sally Squires. Both have thoughtful columns on food and nutrition.