Sustainable diet. What does that mean? a diet we stay on long term? a diet that can be produced long term? one that provides adequate nutrients? A quick look on the net yields: http://sustainablediets.com/what-is-a-sustainable-diet/
"a sustainable diet must taste good and be enjoyable or you may abandon
it. It needs to be affordable and to contain all the nutrients you need
to reach and maintain health and vitality."
And her definition is some of the problem... The purpose of diet is to provide nutrients and energy for the human body. That is all. Taste is a modern problem. Hunger is the best appetizer according to Epicurus and others.
The poor Romans 2000 year ago ate barley portage and barley bread, with bit of fish, goat, and cheese, onions, figs, olive, olive oil, and other stuff. There spicing was local leaves that they found to add savoring. It was sustainable for them, but of that I would only eat fish, cheese, onions ans olives. The wealthy Romans are what they wanted and had as much of an obesity problem as we do.
It is my opinion today that obesity is a attitude problem. We desire to eat good tasting stuff, it is available and cheap so we eat it. We need to eat metered meals of stuff that does not set off the desire for more.
The US government says the Paleo diet is not sustainable. There concern is different. Vegetables cannot be stored fresh for extended time. The US does not produce that much meat and fat required for a complete population on Paleo, so it is not sustainable in those terms. For a individual, it is the most sustainable diet. Add a few potatoes, if you are not addicted to potatoes, and there you have a highly palatable sustainable diet. It is difficult to stay on, if you are living out of restaurants. And yet, there are many places that offer a low carb meal, or equivalent.
The first thing is to get rid of sugar and processed starches. Those are just not foods. The next issue is portion sizes and eating between meals. We need to get our insulin down so that we can see the leptin.
But what do I know.