My comments are in this style. This is a short summary of key ideas.

DGAC 2015 Overarching Themes

Although behavior change is complex, moderate to strong evidence now points to effective strategies to promote healthy lifestyle behavior changes at individual and population levels.

The Problem.

About half of all American adults—117 million individuals—have one or more preventable, chronic diseases that are related to poor-quality dietary patterns and physical inactivity, including cardiovascular disease, hypertension, type 2 diabetes and diet-related cancers.

Obesity

More than two-thirds of adults and nearly one-third of children and youth are overweight or obese.

Few, if any, improvements in consumers' food choices have been seen in recent decades.

High chronic disease rates

High chronic disease rates ... have persisted for more than two decades and disproportionately affect low-income and underserved communities. (In particular the six "diseases" we call metabolic syndrome.)

Healthy Diet

A healthy dietary pattern is higher in vegetables, fruits, whole grains, low or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meats; and low in sugar-sweetened foods and drinks and refined grains.

Strong evidence shows that it is not necessary to eliminate food groups, or conform to a single dietary pattern, to achieve healthy dietary patterns. Rather, individuals can combine foods in a variety of flexible ways to achieve healthy dietary patterns, and these strategies should be tailored to meet the individual's health needs, dietary preferences and cultural traditions.

The Banting Diet suggests that if you have damaged your metabolism, and the evidence is that most of us have, eliminating all high-carbohydrate foods from your diet, is beneficial. The more damaged your system is, (How carbohydrate intolerant you've become.) the more restrictive your diet needs to be. If all you need to do is lose weight, restricting carbohydrates to 100gm a day will do it. If you need to reverse type 2 diabetes, or protect yourself from pre-cancers or Alzheimer's disease, you'll need to be more serious about the diet. You need to change the homeostasis setting of your body, to get the appestat working again, and to restore your normal weight.

Exercise

Current research also strongly demonstrates that regular physical activity promotes health and reduces chronic disease risk.

Change Your Lifestyle

Healthy, sustainable dietary patterns also may provide new themes for ... lifestyle practices that can promote food security now and for future generations and create a "culture of health" at individual and population levels.

Diet and Your Health

Current research provides evidence of moderate to strong links between healthy dietary patterns, lower risks of obesity and chronic diseases, particularly cardiovascular disease, hypertension, type 2 diabetes and certain cancers.

Emerging evidence also suggests that relationships may exist between dietary patterns and some neurocognitive disorders and congenital anomalies. (Like Alzheimer's disease, dementia and birth defects.)

So they say the diet is the key to ALL of the above problems. Metabolic Syndrome, many cancers, Parkinson's disease and Alzheimer's. You can improve your life-time health outcomes.

Evidence on "what works"

There is increasing convergence of research evidence, (This is the alternative stream research.) showing that healthy dietary patterns not only reduce disease risks and improve health outcomes.

The research base reviewed by the 2015 DGAC (This is the mainstream research.) provides clear and consistent evidence that persistent, prevalent, preventable health problems, notably overweight and obesity, cardiovascular diseases, diabetes, and certain cancers, have severely and adversely affected the health of the U.S. population across all stages of the lifespan for decades and raise the urgency for immediate attention and bold action.

The committee refuses to accept that their guidelines don't work. They admit the problem but blame the American people, for failing to restrict the calories they are eating.

The new science on low-carbohydrate high-fat diets, is quite conclusive, I believe.

The correct way to understand how the body works, is to appreciate it a system of hormones and enzymes. Chemical messengers switch systems on and off. They may also switch genes on and off. You have some control over this system, in both what you eat, and when you choose to eat it.