Monumental Study on Why Low-Carb Dieting Works
We finally have a reliable nutrition study. The study was a randomized controlled trial that lasted 30 weeks and all food was provided. This is monumental. I have been so waiting for these kinds of studies to trickle into the mainstream, and here is a good one.
The study tested whether reducing carbs increases metabolic rate. It does. What does this mean? Traditional dieting with focus on calories fails because the process actually slows down your metabolism in response to less food. Two things happen to conspire to keep you fat when you eat plenty of carbs but reduce overall calories:
- you get hungrier for more food
- your body needs less food to maintain itself
This is because insulin is storing energy (fat) rather than using it (metabolism). If you reduce insulin (by reducing carbs) you will use what you eat rather than store it. Very simple, elegant even. This is the carbohydrate-insulin hypothesis that underpins low-carb lifestyles. It explains how weight gain is more about hormones than calories.
The hypothesis is that over the last 40 years, we have increased our average weight and grown obese as a nation because of WHAT we eat, not HOW MUCH we eat. And importantly, the carbohydrate-insulin hypothesis says we got the cart before the horse in our thinking: we eat too much because we are obese, not that we are obese because we eat too much. It may sound counter-intuitive until you sit with the idea awhile. This is what insulin does — it builds. It will take what’s available and build fat or muscle. It won’t break down what you eat for energy. That requires other hormones to be present in larger amounts, which doesn’t happen when you eat carbs. It DOES happen when you eat fats and proteins.
The carbohydrate-insulin hypothesis is why the ketogenic diet works for so many of us. It’s part of the cluster of low-carb eating that includes primal, paleo, lchf, keto, zero carb, and carnivore.
Why Other Kinds of Nutrition Studies Don’t Work
There are two big problems with nutrition studies and why I refer to them as “mostly voodoo.”
- Nutritional epidemiology shows correlation only and is frought with confounding variables that question even the reliability of the correlation shown
- Most nutrition studies rely on self reporting of self-selected foods over weeks or years
Nutritional epidemiology studies have trickled into the mainstream over the last decade, but they have been the very foundation of nutrition research for many more decades. You should know how bad nutritional epidemiology is by now — highly unreliable and overly reliant on statistical analysis that is frought with confounding. They never, I repeat NEVER, show cause, only correlation by their very design. Yet, all the news and social media take them as proof of cause. And most of these studies don’t even reliably show correlation, because the design and analysis have to weed out confounding variables and somehow pick out THE ONE thing that is making the difference in health, weight, or fitness.
Most nutrition studies you see reported in the mainstream rely on self reporting. Do you remember everything you ate yesterday? The amounts? the ingredients? The macros? Will you forget to add the sauce or misjudge the amount or think those two sour balls don’t count? Can you recall last week? Last year? No kidding, imagine a research study basing a finding of “meat eating causes early death” on self-reported data like “I ate approximately 3 servings of beef every week last year” versus “I ate no meat last year” with no accounting for self-reported accuracy, what else was eaten (sugar, grains, oils), or other lifestyle choices, like smoking or exercise (because those who altered their diets in the past often followed other advice from the same authorities).
The very best kind of study is a randomized controlled double-blind, where some people are given one set of meals and the other another set of meals and neither group can cheat or has to self-report anything. Those kinds of studies are unethical and not allowed in our scientific community. Any longer. There is one that was done many years ago.
The Minnesota Coronary Experiment (1968-73) was a double blind randomized controlled trial designed to test whether replacement of saturated fat with vegetable oil rich in linoleic acid reduces coronary heart disease and death by lowering serum cholesterol. It took place in nursing home and six state mental hospitals in Minnesota. What happened with this study? It proved exactly the opposite of what was reported because the researchers reported only partial information. After he died, researchers returned to the data and discovered the fraud.
The experiment sought to prove that saturated fats raised cholesterol and increased death rates. It actually showed that substituting plant fats for animal fats did indeed reduce cholesterol but actually INCREASED death rates.
If your doctor is telling you to lower your cholesterol because it increases your risk of heart attack, they need to do some reading on nutrition and quit listening to agencies compromised by funding with board members beholden to industry. How would things be different today if the truth had been published?