As everyone knows, or bloody well should know, in the scientific world correlation is not causation. However, in the fields of nutrition and chronic disease the conflation of corr. with cause is rampant. Rampant and deadly. Current nutritional dogma, and dogma it certainly is, demonizes meat consumption and glorifies plant consumption. You've heard of the big lie? This is one of the biggest lies around. The lie is based on what is called "epidemiology". Epidemiology works well for the control and tracking of infectious diseases, but when confronted with the explosive "epidemic" of chronic conditions we are currently experiencing, its usefulness is questionable, to put it mildly.
When doing a nutrition "study", the standard investigative tool is the food frequency questionnaire. The "data" derived from said questionnaires is entirely dependent on the subject's memory of how much and how frequently they eat the foodstuffs enumerated in the questions. Can you accurately determine how much of anything you ate over the last year? Didn't think so. Can you accurately remember what you ate over that span of time? And, even if you've written down everything you've eaten, are you honest about it? Or are your answers meant to play to someone's idea of a "healthy diet"?
Then there are the "confounders". Which are circumstances which should be taken into account, but are often discounted, or outright ignored in pursuit of what a researcher seeks to prove. A typical such circumstance in nutritional epidemiological studies is baying to the public that "meat increases your risk of heart disease." Only the putative level attested to by respondents is considered, and not what else a heavy meat eater normally consumes. Such as fries, bread, cookies, ice cream, and the vast panorama of carbage processed food. Meat is essentially guilty until proven innocent, which it almost never is. Only if one is eating very few carbs, or none, can a reasonably statistical inference be drawn about the "dangers" of eating meat.
Such a study has yet to be done, although there are increased efforts to do so in light of the near miraculous ability of ultra low-carb diets to ameliorate, or reverse, a wide variety of chronic conditions. As they say, "More research is needed." Which frequently only means "We need more funding.", but is literally true in the case of low-carb nutritional research.
