The gold standard to establish causation is the 2x blind random placebo-controlled study. There are many of them assessing various types of foods, from meat to lychee to soy and everything in between. Many biomarkers in the body can be studied such as stress hormones, markers of inflammation, lipid panels, arterial wall thickness, etc. If you poke around on youtube, you can find smart people presenting this research! Most of them are health influencers. Personally, I follow Drs. Gregor, Rhonda Patrick, Fung, Mike Hetzel Thoms Delauer and the rest of this particular cohort. They all have their separate biases and areas of interest, such as fasting, muscle gain, veganism, grass-fed beef, ketosis, etc, but if you find the intersection of their work, you'll have an excellent idea what is good and bad for you and how much you can get away with!
To distill two of the most valuable things I've learned:
1. The Mediterranean diet seems to be the healthiest and closest to the Western and American diets, although its actual form has some key differences from the received wisdom. In particular, its pasta is a whole-grain variety and the fish consumption is less than once per day.
2. Most people are not fat-adapted and their bodies do a poor job of metabolizing fat! Typically this requires fasting or other forms of intermittent ketosis to get the body producing fat-burning enzymes. This is likely the source of a lot of conflicting info on fat. It's perfectly excellent for you - if you are fat-adapted, you will use it for energy and won't experience 3pm brainfog. But if you're not, it will very quickly create adipose tissue (body fat!) that continuously emits cytokines (poison) that sabotage your health.
3. Stress alters our metabolism for the worse! Since so many of us are stressed we're not performing proper digestion and not getting the right benefits from what we eat! Breathing exercises, etc. can help improve this.
The Mediterranean diet is only superficially close to the American one. It would be more accurate to speak of separate lifestyles than diets. The relationship to food that Americans have is almost completely alien to what most Italians experience, although with the spread of American culture this might not last beyond a few generations.
It's a bit like what used to be called the 'French paradox' in that American observers mistook a tradition of rich foods as the constant ingestion of such food.
It would if people could stick to the protocols in the studies as designed. In practice RCTs only enable us to estimate the effect of the _offer_ of treatment (the intention to treat estimate) rather than making a direct causal estimate of the treatment itself. Missing data is a particular source of bias in this regard (if people dropped out, you can't know why or the counterfactual of what you would have observed had they stayed in the trial).
To distill two of the most valuable things I've learned:
1. The Mediterranean diet seems to be the healthiest and closest to the Western and American diets, although its actual form has some key differences from the received wisdom. In particular, its pasta is a whole-grain variety and the fish consumption is less than once per day.
2. Most people are not fat-adapted and their bodies do a poor job of metabolizing fat! Typically this requires fasting or other forms of intermittent ketosis to get the body producing fat-burning enzymes. This is likely the source of a lot of conflicting info on fat. It's perfectly excellent for you - if you are fat-adapted, you will use it for energy and won't experience 3pm brainfog. But if you're not, it will very quickly create adipose tissue (body fat!) that continuously emits cytokines (poison) that sabotage your health.
3. Stress alters our metabolism for the worse! Since so many of us are stressed we're not performing proper digestion and not getting the right benefits from what we eat! Breathing exercises, etc. can help improve this.