CrossFit | It Is Time to Bust the Myth of Physical Inactivity and Obesity: You Cannot Outrun a Bad Diet

It Is Time to Bust the Myth of Physical Inactivity and Obesity: You Cannot Outrun a Bad Diet

6
ByCrossFitFebruary 22, 2020

Question
Can exercise alone prevent metabolic disease?
Takeaway
The narrative that exercise alone can prevent obesity and metabolic disease is largely the product of food industry PR campaigns; scientific evidence indicates sugar and carbohydrate consumption, specifically, contributes to disease progression.

In this 2015 editorial, Aseem Malhotra, Tim Noakes, and Stephen Phinney argue that in addition to exercise, specific dietary changes are necessary to prevent or reverse metabolic disease.

A 2015 report from the Academy of Medical Royal Colleges described exercise as a “miracle cure” and argued 30 minutes of moderate exercise five times per week is more powerful than pharmaceuticals for chronic disease management and prevention. Malhotra et al. argue the emphasis on exercise distracts from the primary role diet plays in the causation and potential reversal of cardiovascular disease, Type 2 diabetes, dementia, some cancers, and other metabolically influenced conditions.

Over the past 30 years, Western obesity rates have risen while mean physical activity levels have remained relatively constant. Companies such as Coca-Cola have nonetheless pushed the narrative that lack of exercise is the cause of obesity, obesity is the cause of chronic disease, and no foods or beverages are uniquely harmful so long as we exercise enough to burn the calories they contain. In other words, consumers can continue to drink sugar-sweetened beverages as long as they exercise more.

This tactic is similar to that used previously by Big Tobacco and reflects a concerted effort to sow public doubt and confusion about the clear scientific links between sugar/refined carbohydrates and chronic disease. For one, obesity itself is far from a perfect predictor of disease risk, with 40% of lean individuals presenting dyslipidemia, insulin resistance, and other markers of poor metabolic health. Recent econometric analysis has indicated an increase in sugar consumption across a population increases diabetes risk 11-fold compared to a similar increase in fat or protein consumption (the analysis meets the Bradford Hill criteria for inferring causality from observational data). Recent reviews have argued carbohydrate restriction is a uniquely potent tool for reversing metabolic disease. The work of Noakes and others has even shown carbohydrate is not required for intensive exercise, as individuals adapted to low-carb diets can oxidize enough fat to meet the demands of all but the most intense levels of exertion.

Malhotra et al. conclude public health officials and marketing efforts should reveal the truth: that the framing of exercise as the single solution to metabolic disease is the result of food industry PR campaigns. The solution to the metabolic disease epidemic is likely to come from a reduction in sugar and refined carbohydrate consumption rather than an increase in physical activity without a corresponding change in eating patterns and behaviors.

Comments on It Is Time to Bust the Myth of Physical Inactivity and Obesity: You Cannot Outrun a Bad Diet

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Tyler Hass
February 23rd, 2020 at 10:32 pm
Commented on: It Is Time to Bust the Myth of Physical Inactivity and Obesity: You Cannot Outrun a Bad Diet

One thing we know for sure is that you can run your way INTO a bad diet. As the sports beverage industry knows, endurance athletes are notorious for carb loading before a race, carb refueling during a race and carb recovery after a race. You couldn’t design a better customer for Gatorade than that.


It’s encouraging to see evidence that fat-adapted athletes can perform well in endurance activities. However, it’s been claimed that low carb diets are bad for high-intensity work. This could be due to the fat adaptation period confounding results. Impaired high-intensity performance is not consistent with the observations of CrossFit as reported in 2004 (Zone Meal Plans): “For those eating according to Zone parameters, body fat comes off fast. When our men fall below 10 percent body fat and start approaching 5 percent, we kick up the fat intake. The majority of our best athletes end up at X blocks of protein, X blocks of carbohydrate, and 4X or 5X blocks of fat. Learn to modulate fat intake to produce a level of leanness that optimizes performance.”


A study on CrossFit athletes following either a low-carb keto diet or a control diet:


A Low-Carbohydrate Ketogenic Diet Combined with 6-Weeks of Crossfit Training Improves Body Composition and Performance


There was no difference in performance between the groups, but the low carb group lost more fat. There doesn’t seem to be any reason to fear low carb diets will hurt performance. Sadly for Gatorade, it looks like sugar water is not required for exercise.

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Michael Gomez
February 23rd, 2020 at 4:33 pm
Commented on: It Is Time to Bust the Myth of Physical Inactivity and Obesity: You Cannot Outrun a Bad Diet

Interesting read, but when “Science” argues in favor of an absolute, it forces me to not take their evidence seriously (even if it is something I currently agree with). The diet that fueled the record for 2016 record of the Appalachian trail is something that immediately came to mind.


Excerpt from The NY Times (https://www.nytimes.com/2016/09/19/sports/fueled-by-beer-and-candy-bars-ultra-runner-karl-meltzer-sets-appalachian-trail-record.amp.html):


: “This time, he capped each night with one or two beers and left from rest stops with rainbow-colored Spree candy, Three Musketeers chocolate bars and bacon in his pockets. To save time and keep his energy up, he typically slept less than seven hours a night and instead had an energy drink every 10 miles, downing about five a day. When on another day his support crew found him napping, they gave him a pint of ice cream for a boost.

Though Meltzer averaged 50 miles in 15 hours of running a day, his pace faltered at times. At one point he slept on the trail instead of making it to his support van — and then he slept the next morning on the dirt again. But in the last two days, he gathered strength, running 83 miles nonstop in the final leg to finish Sunday morning at 3:38.“

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On the other hand, maybe “big food” is in cahoots with The NY Times. One thing I know, anyone totting their science around as the absolute answer is the real similarity to draw in alignment with big tobacco. People’s bodies are different, any one solution isn’t for everyone, and with a population approaching 8 billion, that “Somebody” ranges in the millions. My opinion: our ancestors definitely outran a poor diet and Karl Meltzer definitely did as well. Exercise is limitless; Good exercise and diet together are unbeatable.

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jr Wild
February 24th, 2020 at 12:35 pm

The sign of metabolic flexibility -of humans:

Volek, Phinney et all: https://www.sciencedirect.com/science/article/pii/S0026049515003340


I guess ultrarunner Zach Bitter was there as well.


Conclusion

Compared to highly trained ultra-endurance athletes consuming an HC diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3 hour run are similar.


Carbloading was the thing to do, but Prof. Noakes aims to rewrite his nutritional advice in "the lore of running". It is kind of a beneficial to acquire access to one's fat storages of 100 000 kcal, and not solely to rely on carb storages of 2 000 kcal. Especially if you aim to do ultra, where you need 6 000 - 8 000 kcal within the day. The less you need to ingest in the later phase, the better (it robs time to take breaks in the bushes...).

JR

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Ted Leger
February 23rd, 2020 at 11:05 am
Commented on: It Is Time to Bust the Myth of Physical Inactivity and Obesity: You Cannot Outrun a Bad Diet

Sadly, Dr. Benjamin Levine, Professor of Internal Medicine Cardiology and Distinguished Professor of Exercise Sciences at the University of Texas Southwestern Medical Center in Dallas is obviously both brilliant and foolish at the same time. This phenomenon is not restricted to diet and exercise. Just about every discipline known to man has been adulterated. Once an idea gains traction and is taught, very few go back to the original assumptions to determine for themselves the veracity of the idea. And it is even worse when financial interests, or personal esteem, become motivating factors, and the use of fear-mongering, ridicule and condescension are employed. Today, people depend blindly on internet narratives. They prefer unproven theories to empirical evidence. And once they are convinced, they take part in disseminating nonsense as fact. Truth must swim against an overwhelming current of misinformation. I thank God for CrossFit in its fight to resist and overcome the ignorance of a lazy uncritical world.

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Emily Kaplan
February 23rd, 2020 at 3:26 am
Commented on: It Is Time to Bust the Myth of Physical Inactivity and Obesity: You Cannot Outrun a Bad Diet


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Katina Thornton
February 23rd, 2020 at 2:02 am
Commented on: It Is Time to Bust the Myth of Physical Inactivity and Obesity: You Cannot Outrun a Bad Diet

"However, this is little appreciated by scientists, doctors, media writers and policymakers, despite the extensive scientific literature on the vulnerability of all ages and all sizes to lifestyle-related diseases."


If you ask Dr. Benjamin Levine, Professor of Internal Medicine Cardiology and Distinguished Professor of Exercise Sciences at the University of Texas Southwestern Medical Center in Dallas if diet or quality of calories matters, he will emphatically tell you no and then offer you a piece of candy from his desktop candy jar, as if to silence any further discussion on the matter.

Sure, it's every kids dream to believe that 100 calories of candy is equivalent to 100 calories of whole foods. But, shouldn't we outgrow that myth as an adult and look to what the science is actually telling us?

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