Recent youtube talk by Christopher Gardner (he is active in educating people about healthy eating and how to eat healthy for life) :
https://www.youtube.com/watch?v=Gj3o5A1wp5QThe Christopher Gardner definition of healthy seems to include words like grass fed, pasture raised, olive oil, and participants were also allowed to eat in restaurants. His in moderation philosophy caused the low fat and the low carb groups to end up eating pretty much the same way so nothing to compare. Some of his good health tips did cause most participants to lose weight. His study does show that the hypothesized predispositions did not really affect people who exert some effort to eat healthy. Most vegan gurus already know that pretty much everyone will do well on plant based diets and the hypothesized predispositions do not really matter in practice. Healthy lifestyle can easily beat feared genetic predispositions and whatever feared predispositions. Pretty much all of us are descended from starch based agriculture groups so an unrefined starch based diet will pretty much work on everyone bec of our shared helpful predisposition that evolved from eating starch based diets for thousands of years.
I found this 2015 study of Christopher Gardner and I have some disagreements on his definition of what is healthy :
Weight loss on low-fat vs. low-carbohydrate diets by insulin resistance status among overweight adults and adults with obesity: A randomized pilot trial
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The fourth strategy was to promote high nutrient density (Quality). Other Quality concepts included “real food,” “minimally processed,” “seasonal,” “organic,” “grass-fed,” “whole grain,” and “pasture-raised,” depending on diet assignment. Both diet groups received similar instructions to drink water, maximize vegetable intake, and to minimize added sugars, refined white flour products, and sources of trans fats. Participants on the LC diet were asked to consume half an avocado each day (approximately 160 kcal), as well choosing other sources of plant-based fats, including olive oil, nuts and seeds, and nut butters. Hass avocados were provided by the Hass Avocado board and were distributed to the participants. All participants were encouraged to take an active role in making food choices; by preparing their own foods at home, reading labels, and asking for appropriate modifications for restaurant menu items.
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In this video Christopher Gardner starts around 42 minutes :
https://www.youtube.com/watch?v=STIYGDwCXwY