Why is it that these "nutritionists" spend all their time talking about clean eating with no results? Clearly regular people can't eat more vegetables and less

Why is it that these "nutritionists" spend all their time talking about clean eating with no results? Clearly regular people can't eat more vegetables and less Doritos. Maybe we'd take them more seriously if they had a reasonable plan to thin America down. I'm a strong town proponent and advocate (though I live in Portugal where many of these problems never surfaced on the same scale). I'm also a real estate investor. The crux of it is that the priority for urban planning enthusiasts must be education, not mass rebuilding. A large, large majority of people would still rather take out buy a horrible McMansion in a soulless development than buy a smaller, well-built home closer to their neighbours. Showing off wealth and ticking off features is valued over long-term enjoyment of your home and betterment of the community. Is it such a surprise that it's hard to get a large number of folks to do what's best in the long term instead of what they want right now?