Chapter 1 – Introduction

Background

Until the final quarter of the twentieth century, public health dietary advice in the United States (US) and the United Kingdom (UK) focused on minimum intakes, to ensure that populations consumed adequate nutrients. The US 1950s-1970s “Basic Four Foundation Diet” recommended four or more bread and cereal portions daily, two cups or more of milk and two or more servings of meat [12]. The UK favoured micronutrient recommendations; until the first macronutrient guideline was introduced in 1950 with British Medical Association advice that dietary fat intake should provide a minimum of 25% of daily calories [13] [14].

The first public health dietary guidelines to set maximum intakes were those announced by the US Select Committee on Nutrition and Human needs in 1977 [15]. These were followed by UK public health dietary advice issued by the National Advisory Committee on Nutritional Education in 1983 [16]. Dietary recommendations in both cases focused on one macronutrient, fat, and a component part of that macronutrient, saturated fat. The specific targets were to i) reduce overall fat consumption to 30% of total energy intake and ii) reduce saturated fat consumption to 10% of total energy intake.

The dietary recommendations were introduced with the intention of reducing deaths from coronary heart disease (CHD) by reducing fat intake. In 1950, the death rate from all causes for the US was 1.45% [17]. Of these 1,446 deaths per 100,000 people, 589 (41%) were recorded as deaths from heart disease. The death rate from heart disease in America in 1950 was thus 0.59%, approximately 6 people in 1,000. The death rate from heart disease could also be viewed as: of the people who died, heart disease accounted for 41% of the deaths.

In 1970, the overall death rate had fallen to 1.22%, while heart deaths continued to account for 40% of these deaths [17]. The four in ten statistic provided the context for the impetus for change that preceded the 1977 Dietary Goals for the United States announced by Senator George S. McGovern, chair of the Senate Nutrition Committee [18].

The four in ten death rate was quoted in the opening volume of The Seven Countries Study, with reference to data for American men "The urgency of finding means of prevention is sharpest for men in middle age for it is in that group that the social cost of CHD is greatest... Starting with men aged 40 through 59, the follow-up would show CHD causing close to 40% of all deaths in five years. It is understandable, then, that most work on the epidemiology of CHD begins with men of those ages" (p.I-1) [19].

Evidence available and considered

Both the US and UK documents acknowledged that the evidence was not conclusive. Hegsted's introduction to the Dietary Goals for The United States noted "there will undoubtedly be many people who will say we have not proven our point" (p.3) [15]. The UK publication referred to "a strong consensus of opinion" (p.24) [16].

 

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