We choose which nutritional experiment we want to participate in. Here are basic options along with some facts and personal comment.
1. High-Carb Low-Fat (HCLF) Standard American Diet
This diet is the reason for the high and increasing incidence of Type 2 diabetes and that approximately 86 million Americans have become pre-diabetic. More than a third of Americans have become obese eating this way. Heart disease results from this diet and it is the primary cause of death. High levels of glucose in blood have contributed to increases in types of dementia and cancer.
This is the choice for anyone satisfied to have the health profile of the average American. Through advertising, people get plenty of encouragement to keep eating this way. Also, many government institutions and nutritionist advocate HCLF. It is the way most people eat so it is the path of least resistance.
Some people stay thin eating HCLF, even though they regularly have sugary drinks and processed food. Reasons for this are complicated and are not completely known, but to some degree this happens with exercise and calorie restriction. Restricting calories goes a long way toward longevity so there are centenarians who eat HCLF, although overweight centenarians are rare. Also, being thin does not insure health. About a third of diabetics are not overweight.
Dr. Peter Attia wrote a great blog post about this:
2. High-Carb Low-Fat (HCLF) Vegan
A thin person commented to me that he eats HCLF and that he is very healthy. He is a vegan and says he eats lots of fruit. Thinking about this got me started on this post.
Raw fruits and vegetables are extremely healthy. People who switch to this from the HCLF processed food diet typically realize significant improvements in health. For more on this, see the two Fat, Sick, and Nearly Dead documentary videos.
The fructose in fruits is a mild toxin that can only be processed in the liver. Consuming more fructose than can be properly metabolized, as with alcohol, results in conversion to fat that is stored in the liver.
Water is the primary component of the body, but of the three macronutrients found in the body, fat is by far the most prevalent. Carbohydrates are not an essential dietary nutrient as fat- adapted people produce the glucose they need from protein and fat.
I have a concern that a deficiency of fat could eventually cause problems with this diet. In my opinion, consumption of high-glycemic fruits should be minimized and quality fats should be our primary nutrient. Not getting enough quality fats can result in dementia and a level of HDL that is too low.
I do think occasional fasting and raw fruit and vegetable juice fasting is beneficial. Vegetables and some fruit should be part of any diet, but I would not minimize fat for the long term. Getting enough protein is not difficult for vegans; however, they do need to make sure they get enough quality fats.
3. Low-Carb High-Fat (LCHF) Ketogenic, Paleo, and Vegan
LCHF works well for me in terms of general health, blood lipid metrics, body weight, waist size, athletic performance, and energy levels. I also like that it minimizes risk of cancer and dementia. Sometimes I miss eating apple pies, but there are still a lot of great food choices so LCHF is not difficult to maintain. I am not a vegan. However, as long as you get quality fats and not fat from heat-processed vegetable oils, LCHF can be a healthy vegan diet.