Obesity Villains Exonerated

This is an extension of the recent post, “Obesity Villains Reconsidered,” which discusses an interesting 2009 paper in which multiple authors looked closely at many accepted or alleged causes of obesity. One of their reactions was to divide pretty much all those possible causes into two subheadings: “food marketing practices” and “institutionally-driven reductions in physical activity” — which for convenience, they called the “big two.” But they also went on to propose quite a number of other causes, in a “more thorough discussion of factors that may be contributing to the obesity epidemic.”

Myopic emphasis

They proposed that there has been a narrowly focused concentration on two very big concepts, both having to do with energy: how to get it, and how to spend it. At the same time, the characterization of those categories has grown ever more broad. Human nature is such that, in many departments of life, we seem unable to count higher than two. A thing is either this or that. It is either intake or output — but that insistence on duality is a sticking point.

The paper titled “Ten putative contributors to the obesity epidemic” spells out that while each unit of the “big two” contains many problematic elements, there are also quite a number of other potential hazards to worry about. They fall outside the purview of either intake or expenditure, yet still need to be accounted for. This paragraph encapsulates the crux of the problem:

[E]ven though some elements of the big two do very likely play some role in influencing obesity levels, we believe that an unquestioned assumption of their preeminence has led to the possibly ill-advised expenditure of public effort and funds on programs aimed at reducing population levels of obesity and has also reduced the exploration of other potential causes and the alternative obesity reduction programs that might stem from their identification.

Consequently, these authors point the finger at some hitherto blameless suspects. More intriguingly, after examining the cases against a few traditionally acknowledged obesity villains, those factors are let off the hook. Take fast-food establishments. A 2008 study showed that although people might consume a boatload of calories at a restaurant, “they largely compensated by eating less at other occasions…”

Of course, that all transpired some years back. Since then, the evidence against fast food has mounted and multiplied. There are indications that people who eat home cooking absorb less sugar and fat, and have lower cholesterol levels. Also, at home, there is more opportunity for portion control, although that could backfire. (“It’s my kitchen, I paid for the food, and by golly, I’ll eat as much of it as I please.”) Another element of domestic culinary art is that, of course, the (traditionally female) cook has more control over what ingredients go into a meal in the first place.

PE still counts

A 2012 meta-study looked at data from “observational studies, 20 cross-sectional studies, and 8 prospective cohort studies.” However, there were methodological differences between those studies, and the conclusions drawn turned out to be “far from conclusive.” A 2018 paper said it all in the title: “Frequency of Eating Out at Both Fast-Food and Sit-Down Restaurants Was Associated With High Body Mass Index in Non-Large Metropolitan Communities in Midwest.” No doubt, plenty of evidence for either claim could be found by a motivated seeker.

As for Physical Education in schools, the evidence that it has decreased is not convincing, and furthermore, “much evidence suggests that standard PE classes have no appreciable impact on obesity levels.” Again, this was stated in 2008, so it is appropriate to look for something fresher — like two reports from 2023. The first, from the University of Texas at Austin, bluntly states in its title, “Physical Education Policies in Schools Have Not Curbed Childhood Obesity.”

Over the past few years, many states have supposedly adopted the 150-minutes-per-week standard. But…

Researchers found that schools largely disregarded state laws and did not increase the time that elementary students actually spent in PE or recess. Relative to states that did not change their laws, states that passed increases did not see a decline in children’s body mass index, overweight prevalence or obesity prevalence.

“Closer oversight of schools would be needed to improve compliance with state PE laws,” said Paul von Hippel […] who co-authored the study. “Yet, even with better compliance, we estimate PE classes just don’t burn enough calories to make a noticeable impact on obesity. At least not as they’re currently conducted.”

But to balance the scales, another fairly contemporary article is titled, “PE classes vital to children’s physical and mental health.” It quotes pediatrician Dr. Rebecca N. Dudovitz affirming that PE classes are definitely helpful, especially post-pandemic, for both the physical and mental health of children. And as always, there are obstacles to the achievement of necessary goals. In far too many cases…

PE class is the only time exclusively set aside for exercise. That’s particularly true for children who do not have access to safe places to play outside of school. Families of students in underserved communities may not have the same resources or privileges of a safe environment for exercise in their neighborhood.

Do parents need to play a role in ensuring that kids move enough? Absolutely. Dr. Dudovitz makes five recommendations:

  1. Carve out daily time for physical activity
  2. Use fun competition as a motivator
  3. Incorporate nutrition (a healthy diet reinforces performance and ambition to stay fit)
  4. Encourage your child to join a sports program or organized after-school fitness activity
  5. Limit time on video games and cell phones

Your responses and feedback are welcome!

Source: “Ten putative contributors to the obesity epidemic,” ncbi.nlm.nih.gov, November 2009
Source: “Association between eating out of home and body weight,” ncbi.nlm.nih.gov, February 2012
Source: “Frequency of Eating Out at Both Fast-Food and Sit-Down Restaurants Was Associated With High Body Mass Index in Non-Large Metropolitan Communities in Midwest,” ncbi.nlm.nih.gov, Jan 2018
Source: “Physical Education Policies in Schools Have Not Curbed Childhood Obesity,” UTexas.edu, 03/21/23
Source: “PE classes vital to children’s physical and mental health,” UCLAHealth.org/ 04/08/22
Image by Jaguar MENA/CC BY 2.0 DEED

Leave a Reply

Your email address will not be published. Required fields are marked *

FAQs and Media Requests: Click here…

Profiles: Kids Struggling with Weight

Profiles: Kids Struggling with Obesity top bottom

The Book

OVERWEIGHT: What Kids Say explores the obesity problem from the often-overlooked perspective of children struggling with being overweight.

About Dr. Robert A. Pretlow

Dr. Robert A. Pretlow is a pediatrician and childhood obesity specialist. He has been researching and spreading awareness on the childhood obesity epidemic in the US for more than a decade.
You can contact Dr. Pretlow at:


Dr. Pretlow’s invited presentation at the American Society of Animal Science 2020 Conference
What’s Causing Obesity in Companion Animals and What Can We Do About It

Dr. Pretlow’s invited presentation at the World Obesity Federation 2019 Conference:
Food/Eating Addiction and the Displacement Mechanism

Dr. Pretlow’s Multi-Center Clinical Trial Kick-off Speech 2018:
Obesity: Tackling the Root Cause

Dr. Pretlow’s 2017 Workshop on
Treatment of Obesity Using the Addiction Model

Dr. Pretlow’s invited presentation for
TEC and UNC 2016

Dr. Pretlow’s invited presentation at the 2015 Obesity Summit in London, UK.

Dr. Pretlow’s invited keynote at the 2014 European Childhood Obesity Group Congress in Salzburg, Austria.

Dr. Pretlow’s presentation at the 2013 European Congress on Obesity in Liverpool, UK.

Dr. Pretlow’s presentation at the 2011 International Conference on Childhood Obesity in Lisbon, Portugal.

Dr. Pretlow’s presentation at the 2010 Uniting Against Childhood Obesity Conference in Houston, TX.

Food & Health Resources