The intention of this comment is to advocate for evidence-based healthy living content on steemit. I think @alexander.alexis comment highlights the crux of the broader issue for healthy eating. People are going to move in the path of least resistance when making food choices. Low-fat took off as a result of USDA recommendations, however foods marketed as low-fat are not always whole foods and therefore not always healthy and within other healthy eating guidelines (e.g., high in sugar or refined starches). Without in-depth nutritional education, the package label makes those food appear to be a "healthy choice."
Keto represents a pendulum swing from the low fat approach to low carb. The food industry could do the same thing with keto, make a low carb snack packed with trans-fats, slap on a keto approved label and you don't have a healthy food, just a reversed unhealthy situation. Fixating on a specific macronutrient or even a specific eating regimen accounts for neither the bigger nutritional picture nor the broader context of an overall lifestyle.
Regardless, to be recommended by the USDA, it appears keto diet advocates still need to present longitudinal and replicable research demonstrating evidence that it: 1) reduces the long term risk of heart disease, stroke, diabetes and metabolic syndrome, 2) is a sustainable lifestyle based approach, and 3) correlates with a longer lifespan (not only of quantity, but also of quality life).
Though on another level, as a society we need to have conversation broader than specific diet plans. Positive impacts on global health related to food relies heavily on evidence-based nutritional research. And, the application of that research will have to take into consideration that the average person is not going to count their carb to fat ratio on a daily basis.
David Katz sums up this point poignantly in his relatively recent article: Can we say what diet is best for health? "We need less debate about what diet is good for health, and much more attention directed at how best to move our cultures/societies in the direction of the well-established theme of optimal eating, for we remain mired a long way from it" (https://www.annualreviews.org/doi/full/10.1146/annurev-publhealth-032013-182351). I recommend this article for reliable up-to-date information on nutritional approaches.