Gaining weight? Maybe you should blame nutrition labels

Dieters beware: Food and restaurant labels might be sabotaging your calorie-counting efforts.

So found a study published in the current edition of the Journal of the American Dietetic Assn. Researchers from Tufts University took commercially prepared foods -- both prepackaged and from restaurants -- and analyzed them in a bomb calorimeter. The measured energy values of 10 frozen meals purchased from supermarkets averaged 8% more than originally stated, and foods from 29 restaurants (both fast-food and sit-down venues) were on average 18% more than reported.

That hidden – and unwelcome --  extra can fool dieters who don’t have the time to cook their own meals into thinking they’re cutting their caloric intake.

It certainly undermined the efforts of Susan B. Roberts, lead author on the study. The Energy Metabolism Laboratory director said she originally conceived of the idea for the experiment after designing two diets – one that required home-cooked meals, and another that did not. Roberts tested the diets out on herself, and her frustration quickly began to mount. In her home cooked-meal diet, she had lost weight consistently and on target. The no-cook regimen, however, was another matter.

"I wasn’t losing any weight," Roberts explained in an interview. "This was ridiculous. I came into the lab one day and thought, something’s not adding up -- I think there’s more calories in these foods than there should be."

Roberts put her theory to the test. The results? A Lean Cuisine shrimp and angel hair pasta label says it's 220 calories (which works out to 250 calories of gross energy, the study calculates). The Tufts team pegged gross energy at 319. Denny's dry toast lists 92 calories (97 kcal of gross energy). Instead, it let off a whopping 283 calories.

The discrepancies were a little less extreme than those in the Pirate's Booty scandal back in 2002, when a suspicious Good Housekeeping employee tested the apparently low-fat snack (label: 2.5 grams of fat) and found it had 8.5 grams, more than three times the stated amount. And to be fair, some foods came in under caloric value (a serving of Domino's thin crust cheese pizza had 141 calories, 33% less than expected). But why did most foods seem to err in excess? Roberts said it was likely because "package manufacturers are just playing it safe."

"The FDA regulations are much more punitive, much more stringent on underproviding than overproviding," the scientist said. "It’s an old style mentality: 'People need to be given what they pay for.' "

Roberts' advice to dieters? Don't starve yourself -- just know what you put into your body. "If you want to lose 10 pounds, you can do it with food. Food is the best way. But by eating at home, you’ll have a much easier time."

In any case, if you’re eating at a place where “dry toast” earns you 283 calories, you’re probably not on the low-calorie bandwagon to begin with.

-- Amina Khan

Photo credit: Ed Ou / Associated Press

Comments

[David S]

A bomb calorimeter is not an appropriate means of measuring usable Calories. Two reasons: First, it burns the nitrogen in protein to inorganic products, and this releases energy that our bodies do not release and cannot utilize; this makes the usable Calorie content appear to be higher than it is. Second, dietary fiber is also fully burned in a bomb calorimeter to inorganic products, thus releasing more energy than would be released/utilized in our bodies and again making the usable Calorie content appear to be higher than it is. The appropriate method to estimate Calories in a sample of food is to perform Proximate Analysis to determine the amounts of carb, fat, and protein (and dietary fiber, if possible) in a sample of the food, then apply the Atwater factors of 4 Cals per gram of carb and protein, and 9 Cals per gram of fat, and an appropriate factor for fiber, depending on the type(s) of fiber present. Perhaps Susan B. Roberts accounted in some way for these errors, but there was no mention in the article.

[Tracy]

We should not always rely on food and restaurant labels, it's still best to educate ourselves and be aware of our food intake.

Tracy, Status Now

[Dana]

Besides having a sample size of ONE, there's too much wrong with this study to even begin to list. Did she take into account the extra 2 hours of light activity required to cook the meals? The enzymatic activity of fresh food vis-a-vis frozen? The unknown effects of satiety-decreasing chemicals, food-analogous substances, etc. in the frozen foods?

[Jason S]

perhaps her failure to lose weight in the above example could more likely be attributed to the ingredients that make up these calories rather than the raw calorie count. Prepared foods are many times highly processed with preservatives, growth hormones (they don't just make the animals twice their natural size) high fructose corn syrup, partially hydrogenated oils, etc. Some of these ingredients are less likely to be present in home prepared meails.

[Matt Stone]

If you have to be "aware" of your food intake, then your metabolism is not operating correctly. Keeping track of calories in and calories out should take no more focus than keeping track of oxygen in and carbon dioxide out. A well-functioning human doesn't have to even think about such things - which can really be defined as an eating disorder if anything. Besides, gaining a pound per year from age 20 to age 60 represents 1/10th of a teaspoon of peanut butter stored each day. Good luck keeping tabs on such a tiny amount with a food scale and the "calories burned" readout from the Elliptical machine. This is a much more insightful perspective on what's really going on:

http://www.180degreehealth.com/insulin-calorie-green-house.html

[smilinggreenmom]

Our family understands the confusion with food labels all too well unfortunately. Our son has food allergies and we have had to try to decipher labels and terms to the best of our ability. He is much better now with handling certain foods since taking his Vidazorb probiotic, but we have to still be very careful at avoiding some of the serious allergens for him. I would love to see things improve!

[Mark]

Good point David S! I was thinking the exact same thing.

[Alyson Z. Mar. RD]

Consistency during preparation will continue to be an issue with restaurants in regards to how accurate their nutrition facts are no matter what. As people begin to rely on nutrition facts more and more, restaurants may feel the need to keep tighter control over their preparation practices. Even laboratory testing cannot account for variation in human preparation. Companies like the one I work for, (www.menucalc.com) can help restaurants calculate the nutrition information for their dishes, but can’t control the force with which a line cook squeezes sauce onto a plate.