The Centers for Disease Control provides the most accurate estimates of obesity prevalence in the US, based on National Health and Nutrition Examination Survey (NHANES) data. They just released data for the 2015-2016 survey period, and it doesn’t look good.
Since the turn of the 21st century, it has looked like the rate of increase of obesity prevalence is slowing. Many of us were hoping that it would plateau, and perhaps eventually decline. Yet the latest NHANES data show that obesity has been increasing at its maximum historical rate since 2011 in both adults and youths, and is now 39.8 percent in adults, 13.9 percent in children age 2-5, 18.4 percent in children 6-11, and 20.6 percent in adolescents 12-19.
Since the CDC release doesn’t provide a graph showing obesity prevalence over the whole history of NHANES surveys, I’ve created my own:
Since 1961, the prevalence of obesity in US adults has increased by 2.95-fold. According to recent research, the lifetime risk of obesity in the US is greater than 50 percent, meaning that most people will have obesity at some point in life. This is a very serious public health problem and I believe we need to get serious about addressing it. As I explained in the last chapter of my book, our efforts thus far have been halfhearted, largely due to the congenital aversion of US citizens, politicians, and industry executives to further regulation of the food system.
Garrett says
Within adults, is there any correlation between obesity and age? I would assume so since the rate is lower for children.
Given that, If age group obesity rates stayed static, what would be the forecast for the adult obesity rate given the expectation for aging demographics over the next few decades?
Stephan Guyenet says
Hi Garrett,
These data are age-adjusted and so don’t reflect changes in population age structure. There is a definite association between age and obesity. Risk increases throughout most of the lifespan, and then decreases among the elderly (~70+ years).
thhq says
That’s discouraging.
Mary says
It looks like it starts going up faster around 1980. What changed then?
Stephan Guyenet says
Hi Mary,
It’s impossible to know for sure, but my best guess is 1) continuation of the diet, food environment, and lifestyle trends that have been gradually fattening us for the last century, and 2) rapidly declining cigarette smoking rates.
http://wholehealthsource.blogspot.com/2012/02/cigarette-smoking-another-factor-in.html
It’s worth noting that the shift in the rate of increase in obesity that happened around ~1978 may look artificially sharp because the data points are widely spaced. In reality the shift may have been more gradual, although there was obviously a change in rate around that time.
Alberto Gómez Torralbo says
Nutritional pyramid
thhq says
A term similar to metabolic syndrome is metabolic inflexiblity, and maybe more useful for describing the obesity crisis.
https://www.ncbi.nlm.nih.gov/m/pubmed/18765680/
The most common inflexibility is for simple carbohydrates, resulting in insulin resistance. While reduction of carbohydrates is an effective way to reduce blood glucose and can help weight loss, the root cause for the loss of flexibility is sedentary behavior.
https://www.ncbi.nlm.nih.gov/m/pubmed/28543022/
thhq says
And the worst of the sedentary behaviors is probably sitting. University of Colorado is currently recruiting participants for a sitting study.
https://clinicaltrials.gov/ct2/show/NCT02258438
One paleo behavior we have lost, to our detriment, is the ability to do a flat-footed resting squat.
glib says
i moved close to work 3 months ago. What was a 40 minutes drive is now a 12 minutes walk. I even go back for lunch and a little sunbathing or come to the office after dinner if I am finishing something urgent. I am tying my belt two holes down now, one more hole and I will have to use some belts I have not used since my 30ies.
Stephan Guyenet says
That is cool. I believe active commuting is one of the best things you can do for your metabolic health, long-term weight regulation, and mental health.
Now I’m going to jump on my bike and commute to the library. I work from home but I “commute” to work at my local library in the morning as an excuse to get some exercise.
Antonio says
A much more interesting graph would show over time trends in bmi. We could see not only how bmi is increasing over time but also how it is changing in distribution. This graph only quantifies trends in the cut off values. A lot of different things can be going on and we would still see the same graph. Does anyone have access to the raw data? thanks
Stephan Guyenet says
Hi Antonio,
I graphed US mean BMI over time back in 2014. There is a very tight correlation between mean BMI and obesity prevalence in the US, suggesting that using the prevalence data is not misleading.
http://wholehealthsource.blogspot.com/2014/04/more-graphs-of-calorie-intake-vs-bmi.html
The reason I don’t use it here is that I wasn’t able to get mean BMI data for more recent time points. I’m sure you could calculate it using the raw NHANES data but it would be time consuming.
You can find graphs of the BMI distribution change over time (using Google image search), but I haven’t found any that are up to date. These distributions have been used to argue that the actual changes over the course of the obesity epidemic haven’t been very significant. I disagree with this interpretation and I think the problem is that most people aren’t used to interpreting distributions. The increase in obesity prevalence in the US is obvious to anyone who is old enough to have known life before the “obesity epidemic”.
glib says
I agree, and even better visceral fat trends (fatty liver in particular).
Guiseppe says
I think changes in ambient temperatures could have played a role in this. For example the use of air conditioning (and heating) in the homes went up considerably during the past several decades: 2.bp.blogspot.com/-vff1iirVIWU/TlgnhBxQV8I/AAAAAAAAA_4/pzjyxCmzzfo/s1600/air-conditioning.jpg. US households probably use more energy for A/C than the rest of the world combined.
My understanding from recent reading on the subject, is that either high or low indoor temperatures can induce some weight loss, as will a fluctuation in the temperature. Fluctuations in temperature could be a type of stress on the body, almost like exercise; the sweating induced by elevated temperatures, the shivering induced by drop in temperatures.
What seems to give the most weight gain is a stable around 22°C temperature when using clothes (and closer to 30°C if being naked) – «the thermal comfort zone», as mentioned in the articles linked below. In one study it was shown that a change from 22°C to 16°C increased energy expenditure by about 170 calories. The study showing that «10 d[ays] of cold acclimation (14-15 °C) increased peripheral insulin sensitivity by ∼43% in eight type 2 diabetes subjects» is very interesting (www.ncbi.nlm.nih.gov/pubmed/26147760?dopt=Abstract). Another found significant health benefit for diabetics using hot tub therapy (30 minutes daily for 3 weeks): http://www.nejm.org/doi/full/10.1056/NEJM199909163411216
If the indoor heating systems could be programmed to have more fluctuating temperatures, maybe mimicking the natural circadian and annual rhytm (colder at night, colder in winter), perhaps this could be very helpful for some obese people.
Couple of articles on the subject:
http://www.tandfonline.com/doi/full/10.1080/09613218.2017.1307647
http://www.leanhigh.com/weight-loss/tips/what-is-thermogenesis-and-why-is-it-important-for-weight-loss#heading15
Oliver Chapman says
You are so right Stephan as a PT and gym owner I see how much of an upward battle we are fighting from misinformation to extreme obesity inducing environment. Even though people want to lose weight, it really is an uphill battle.
I think until a real effort using the current scientific data is used in government to help make a healthier overall environment with less processed foods and better education things won’t change that much.
Don Brown says
This is not surprising. What we have is a perfect storm of BIG PROCESSED FOOD and BIG PHARMA working together to extract as financial gain as possible from us Humans. 100 years ago we were thinner, more energetic and had much fewer diseases. The simple solution to obesity is to STOP EATING ANYTHING MADE BY MAN. My dear friend Jack la Lanne left us all a powerful message- Nutrition is King, Exercise is Queen, put them together and you have the Kingdom of Health….” EAT FOOD AS CLOSE AS IT COMES FROM THE GROUND” was his mantra…..
Sorry about my rant but the solution is simple- EAT REAL FOOD, EGGS, GRASS FEED Meats, Lots of organic NON GMO veggies and move every day as much as often. Take a sprint 1-2 times per week to keep your heart from clogging and you can kiss most diseases good-bye.
Or………
Buy and eat what BIG FOOD tells you too……Then when you get sick–go visit BIG PHARMA and they will have a quick solution that temorparyly solve your problem only to create a new one that will require a new DRUG from BIG PHARMA called CHEMO…which will do a great job at prolonging your death. You decide.