Does Physical Activity Calorie Equivalent Labeling Make Sense?
Wednesday, February 11, 2015
One of the most common misconceptions in the simplistic “eat less – move more” narrative, is equating the calories in a food with the amount of work that would be needed to burn those calories (e.g. X potato chips equal y minutes of riding your bike).
Not only are things rarely that simple (given that individual “fuel efficiency” varies widely based on size, age, conditioning, fitness, and probably countless other variables), but these messages just serve to reinforce the notion that exercise (or for that matter any form of physical activity) is indeed a viable strategy to “burn off” excess calories.
For what it’s worth, a study by Viera and Antonelli from the University of North Carolina, published in Pediatrics, shows that physical activity calorie equivalent labeling (PACE) has no more impact on parents’ fast food decisions than showing calories only.
The study was conducted as a national survey of 1000 parents randomized to 1 of 4 fast food menus: no labels, calories only, calories plus minutes, or calories plus miles needed to walk to burn the calories.
After excluding implausible answers, the researchers were left with 823 parents, with the mean age of the child for whom the meal was “ordered” being about 9.5 years.
While parents whose menus displayed no calorie label ordered an average of 1294 calories, those those shown calories in any form ordered about 200 calories less, irrespective of whether they were shown calories only, calories plus minutes, or calories plus miles.
Despite this lack of difference, when parents were asked to rate the likelihood each label would influence them to encourage their child to exercise, 20% of parents reported that calories-only labeling would be “very likely” to prompt them to encourage their children to exercise versus 38% for calories plus minutes and 37% for calories plus miles.
From these findings the authors rather enthusiastically conclude that PACE labeling may influence parents’ decisions on what fast food items to order for their children and encourage them to get their children to exercise.
Both of these conclusions are rather optimistic at best.
As for influencing the parents choice, there was clearly no difference between wether or not calories were shown alone or equated to time or miles – calories alone did the job.
And as for whether equating calories to activity would do anything at all in terms of parents actually getting their kids to do more, I would remain rather sceptical till I actually see a study that reliably measures physical activity.
Overall, this study does nothing to alleviate my concerns about equating food calories to calories burnt – this is a narrative that both the food and the fitness industry often favours in their marketing – the former to suggest that with enough physical activity, you can eat as many calories as you want; the latter to suggest that exercising is the best way to lose weight.
I for one would be perfectly happy to just see calories on menus.
@DrSharma
Edmonton, AB
Wednesday, February 11, 2015
Whether a parent orders 1294 calories for a 9.5 year old, or 1094 calories; it is still too much.
Wednesday, February 11, 2015
The fact that labels, in general, may increase customer nutrition awareness. This should be a reason for PACE or even just kcal labeling. No matter the labeling, isn’t it a field expedient way to positively impact public health (not including the positive psychological effects)?
I completely agree that healthcare professionals OVERestimate the accuracy of the 3500 equation & how many kcals you “burn” via exercise!
Saturday, February 14, 2015
Hi Dr. Sharma,
The fitness industry does a lot of things that are junk. Calorie labels are wildly inaccurate- as much as 85 % – Dr. Jeffrey Friedman noted.
Physicist, Richard Philips Feynman , noted that nobody eats calories. “When we hear of calories, nobody actually eats calories , rather, that is only the amount of heat energy in the food.”
The human body derives its energy from the (chemical) energy contained in the chemical bonds of the food we digest. It then converts this into heat and kinetic energy.
The body operates like a chemistry set- a chemical cascade.
Feynman noted that energy is not anything concrete or material. It is a quantity, a number only- nothing more. Nor is it a description of any mechanism.
Feynman noted we do not even know how much energy there is. It does not come in little blobs of a definite or certain amount. It is NOT that way at all ! I think we cannot fully account for all of the energy entering and leaving the human body- it is too complicated to actually measure ENTIRELY. The conservation of energy principle is not that well understood said Feynman . Energy comes in a very large number of different forms. There is a different formula for each one. In order to even udnerstand the conservation of energy we MUST have the different formulas for each of the various forms of energy.
Feynman notes: There is a “quantity” in nature ( a number physicists can calculate) that does not change when something happens. This principle is a very peculiar and a very abstract idea. A very strange mathematical finding. How this explains fat cells gone wild… It does not.
The fitness industry grossly abuses the conservation of energy principle ( it is a rampant problem) which does not at all ADDRESS :
* Fat cell regulation/hoarding/dysregulaiton SPECIFICALLY ( as obesity is about fat mass/cells specifically not just overall weight or mass)
*How the body handles, uses, absorbs or partitions energy
*What form of mass is gained or lost specifically ( bone, organ, muscle fat all or any combination of all)
* The fact that the body has a mind of its own and its own agenda regarding our mass and fat- and the many, many INVOLUNTARY measures it can invoke to exert its control.
* Body composition specifically and even differences in body composition among various individuals
There are plenty of VERY BIG BUT but very lean humans ( human sirloin meat) and there are plenty of fairly small, but very fatty human Zucker rats ( tiny fatty human hamsters or human salami) . I sympathize and am just pointing out the differences and how conventional views cannot even begin to explain those observations.
Lastly, there is also the skinny fat phenomenon too.
You are right. “Eat less, move more” is nothing more than a silly nostrum borne of ignorance- total ignorance. Obesity is poorly understood. The Lancet has a new article out where researchers show how “eat less , move more” is not how it works and how it is not a solution for obesity. The less than 1 % who succeed long term only have obesity in remission. They are not cured , nor are they the same as a normal never-obese lean person.
We need to learn MUCH more about cells in general, not just fat cells.
Best wishes,
Raz