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Reader,

This week, we’re exploring a fascinating subject: nutrition studies. They’re a rich resource of information about how the food we eat impacts our health. Yet, as you’ve probably noticed, they often appear contradictory and confusing. Today, we’re investigating why this is and what it means for your daily diet.

The crux of the matter lies in the types of studies typically conducted on nutrition. Most are epidemiological studies. These involve observing and analyzing the patterns, causes, and effects of health and disease conditions in specific populations. For example, a researcher might notice that people who consume more fruits and vegetables tend to have lower rates of heart disease. This type of research can provide essential clues about the links between diet and health.

However, and this is crucial, epidemiological studies don’t prove causality. They merely reveal correlations, which are associations between two factors. Let’s clarify that with an example: If the majority of people who wear red shoes happen to love pizza, it doesn’t mean wearing red shoes makes you crave pizza. It’s a correlation, not a cause.

To truly establish cause and effect, you need randomized controlled trials (RCTs), the gold standard in medical research. In an RCT, participants are randomly assigned to different groups: a treatment group (that receives the intervention) and a control group (that does not). If the treatment group shows significantly different results, we can say with confidence that the intervention caused the difference.

Unfortunately, RCTs are rarely used in nutrition research because they are costly, lengthy, and challenging to implement. Imagine asking a group of people to follow a specific diet for several years while maintaining all other lifestyle factors constant. It’s an enormous task!

Moreover, the Hill criteria 1, a set of nine principles to determine causal relationships, are often overlooked in nutrition studies. These criteria include factors like strength of association, consistency, specificity, temporality, and more.

Let’s consider the famous example of calorie restriction in mice. By doing a RCT with different cohorts that all were restricted at different amounts, it was obvious that the mice whom calories were slightly restricted had the longest and healthiest life. However, when they did an epidemiological study on the fattest group of mice (those who could eat as much as they want), the study showed that those who were the most obese actually were the healthiest and lived the longest.

Translate that to the real world. What you'll find are companies and industries doing "studies" that prove you need to buy their product above anything else. Sorry, one handful of hazelnuts each week isn't going to make you live longer.

So, what does this all mean for you?

We’re not saying you should ignore all nutrition advice. On the contrary, what you eat undoubtedly impacts your health. It’s just that our understanding of nutrition is still evolving, and some of the so-called “evidences” are less robust than you might think.

If someone promises you a diet that will change your life, tread cautiously. They might be overselling the evidence, or worse, trying to sell you a supplement. Always remember to take such claims with a grain of salt (pun intended!). Prioritize a balanced, varied diet, regular physical activity, and adequate sleep over the latest fad diets.

So my approach to solving this nearly impossible puzzle is to experiment with different methods of restricting calories. I try to eat as minimally processed foods as possible but don't shy away from dessert if I'm out to dinner with my wife and finally have a night away from the kids. Life is about living after all!

In terms of calorie restriction Peter Attia does a good job breaking them down into 3 categories that I'll explain in more plain language than he does :)

1. Counting calories - using apps like MyFitnessPal you log everything you eat. This leverages the Hawthorne Effect (2) which says that you'll change your behavior when you know it's being observed. So merely by logging what you eat will force you into eating "better" - whatever that means for you.
2. Time Restriction - also known as Intermittent Fasting which is where you set a specific period of time in which you can eat. The idea being if you limit your window enough you won't be able to overeat because you simply cannot consume enough calories during that time. In my experience I always saw this as a challenge and I would usually win. The net results was despite me fasting for 18 hours per day, I still overate and ended up gaining weight #fail
3. Food Restriction - this is where you pick a specific diet that eliminates certain foods. By way of limiting what you can eat you tend to eat less. This is where most of the fad diets fall into such as Paleo, Keto, Plant-based, etc. In my experience this is effective in the short term but unsustainable long term. In my experience, eating vegetarian for 8 years, Paleo for 5, and Keto for 2, I found that there is more religion than science used as the rationale to eat a certain way. But to each their own.

I hope this helped break down some of why diet and nutrition aren't the solutions to all our health related problems and gave you a fresh, more data-driven, approach to understanding these challenges.

If you like this newsletter and want to help it grow make sure to share it! And if someone has sent you this newsletter click here to sign up and receive my insights, results, and experimentation on how to live a healthier and more fulfilled life.

Stay resilient, stay inspired, and here's to living a bulletproof life!

Ben

p.s. If you want to dive deeper into all this I highly recommend Peter Attia’s new book Outlive. You can get it by clicking here which also helps support this newsletter with a small affiliate commission at no added cost to you.