2. The scientific evidence for dietary claims

The full text of the book published by Bloomsbury. Author Peter Thomson

Dietary information for a healthy life should be based on robust scientific evidence.

Health depends on eating a broad and balanced diet ( and not too much of it ), getting plenty of exercise every day and a good night's sleep every night.

According to Professor David Raubenheimer of the University of Sydney we, in common with many animals, have an inbuilt system to eat the right amount of protein, carbohydrate, fat, sodium and calcium in the diet. But if small amounts of protein are mixed with larger amounts of carbohydrate we will eat too much carbohydrate in order to get the protein. Even worse, manufactured foods designed to taste like protein encourage us to eat and eat, because our need for protein is not satisfied.

Separating protein meals from starch meals allows our natural balancing mechanisms to work properly and we have a natural ability to eat the right amounts of protein and starch.

"Researchers are reporting in a new study that making five health lifestyle choices might prolong your life by at least 10 years. Those habits are: eating a healthy diet, exercising regularly, not drinking too much alcohol, not smoking, and maintaining a healthy body weight. The study, partly funded by NHLBI, appeared in Circulation external link , a publication of the American Heart Association."


What constitutes a broad and balance diet? A good range of fresh meat, fish, eggs, cheese,  fruit and vegetables and grains / starches. Not too much of each.

"Description of the DASH Eating Plan

DASH is a flexible and balanced eating plan that helps create a heart-healthy eating style for life.

The DASH eating plan requires no special foods and instead provides daily and weekly nutritional goals. This plan recommends:

  • Eating vegetables, fruits, and whole grains
  • Including fat-free or low-fat dairy products, fish, poultry, beans, nuts, and vegetable oils
  • Limiting foods that are high in saturated fat, such as fatty meats, full-fat dairy products, and tropical oils such as coconut, palm kernel, and palm oils
  • Limiting sugar-sweetened beverages and sweets."https://www.nhlbi.nih.gov/health-topics/dash-eating-plan
  • The DASH Diet, 20 Years Later

Avoid too much highly processed foods.

Avoid trans fats -synthetic fat products.

Keep salt intake low : https://hyper.ahajournals.org/content/early/2018/03/02/HYPERTENSIONAHA.117.09928

And if the Hay diet helps you achieve this then it is an excellent diet to follow.

Much of the world relies on the US dietary guidelines - but can we rely on them?

A report published by the BMJ in 2015 and 2016 highlights a number of issues

Feature Nutrition

The scientific report guiding the US dietary guidelines: is it scientific?

BMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h4962 (Published 23 September 2015) Cite this as: BMJ 2015;351:h4962


The scientific report guiding the US dietary guidelines: is it scientific?

BMJ 2016; 355 doi: https://doi.org/10.1136/bmj.i6061 (Published 02 December 2016) Cite this as: BMJ 2016;355:i6061

This report highlights the risk of bias and conflict of interest.

"For example, a bias towards the longstanding view that saturated fats are harmful can be seen in the report’s designation of them, together with sugar, as a new category it calls “empty calories.”2 The report repeatedly mentions the need to reduce “sugar and solid fats,” because, “both provide calories, but few or no nutrients.”2 Yet this pairing is unsupported by nutrition science. Unlike sugar, saturated fats are mostly consumed as an inherent part of foods such as eggs, meat, and dairy, which together contain nearly all of the vitamins and minerals needed for good health. "

"Much has been written about how industries try to influence nutrition policy, so it is surprising that unlike authors in most major medical journals, guideline committee members are not required to list their potential conflicts of interest. A cursory investigation shows several such possible conflicts: one member has received research funding from the California Walnut Commission61 and the Tree Nut Council,62 as well as vegetable oil giants Bunge and Unilever.63 64 Another has received more than $10 000 (£6400; €8800) from Lluminari, which produces health related multimedia content for General Mills, PepsiCo, Stonyfield Farm, Newman’s Own, and “other companies.”65 And for the first time, the committee chair comes not from a university but from industry: Barbara Millen is president of Millennium Prevention, a company based in Westwood, MA, that sells web based platforms and mobile applications for self health monitoring. While there is no evidence that these potential conflicts of interest influenced the committee members, the report recommends a high consumption of vegetable oils and nuts as well as use of self monitoring technologies in programs for weight management."

I will state clearly at this point that I don't receive payment from anyone. The advertising on this website just about covers the cost of hosting it.

So where should we look for the scientific evidence?

"The Women’s Health Initiative (WHI), was the largest nutrition trial in history...Nearly 49 000 women followed a diet low in fat and high in fruits, vegetables, and grains for an average of seven years, at the end of which investigators found no significant advantage of this diet for weight loss, diabetes, heart disease, or cancer of any kind"