I was raised on a dairy farm and ate plenty of meat and eggs until about twenty years ago. I started doing nutritional research, and a decade pr so after that my family made some major dietary changes. I'm just paying attention to what the data are telling me: The scientific evidence came first.

The answer to the American health crisis is the food that each of us chooses to put in our mouths each day. It's as simple as that.

Perhaps it is a testament to the power of modern marketing savvy that an obese man with heart disease and high blood pressure became one of the richest snake oil salesmen ever to live, selling a diet that promises to help you lose weight, to keep your heart healthy and to normalize your blood pressure.

One way to identify the optimal human diet, pretty obvious to all but fundamentalist reductionists, is to survey and compare populations as they already exist, and see what they eat and how healthy they are.

In every respect, vegans appear to enjoy equal or better health in comparison to both vegetarians and non-vegetarians.

In the next ten years, one of the things you're bound to hear is that animal protein is one of the most toxic nutrients of all that can be considered. Quite simply, the more you substitute plant foods for animal foods, the healthier you are likely to be.

You can't be protein deficient without being calorie deficient because even if you take the foods that have the least amount of protein in them, let's say potatoes, for example, or rice at 8 or 9%. That's the figure we more or less need.