RESULTS Our findings suggest that consumers have a relatively poor underst and ing of a healthy diet .
The literature also demonstrates that there is poor evidence on the health protective effects of single foods or nutrients .
We further show that low SES is the single consistent risk factor for not adhering to a healthy diet .
Our review of the literature on determinants demonstrates that intentions , habits , self-regulatory skills , and the social and physical environment are the most important determinants of a healthy diet , which are in turn amenable to change by intervention strategies with varying levels of effectiveness .
Educational interventions generally show a limited effect on practising a healthy diet whereas interventions targeting habitual behaviour and /or the physical environment seem more promising .
In view of the large number of people who are concerned about their diets and make attempts to change their dietary patterns , we conclude that it is crucial to gain a better underst and ing of both the automatic and environmental influences that are responsible for people not acting upon their good intentions for diet change
OBJECTIVE To discuss healthy diet from a psychological perspective by considering definitions of healthy diet in terms of consumer underst and ing ; the health effects of specific dietary elements in terms of overweight and ( chronic ) illness ; the prevalence of healthy diet ; the psychological and environmental determinants of healthy diet ; and the psychological interventions that have been design ed to promote healthy diet .
Some problems with Cochrane reviews of diet and chronic disease
The sum of evidence -based nutrition has to be more than a Cochrane-type meta- analysis of r and omised controlled trials ( RCTs ) . Most of the evidence base in nutrition is observational , especially cohort studies . RCTs of diet change through to disease outcome are uncommon and the change has usually been addition or removal of only a single food component . Trials with whole diets through to disease outcome are rare and dietary changes made by individuals are unlikely to be an exact copy of the prescription . It is hard to even imagine a trial in which half ( r and omised ) of a large group of middle-aged people agree to avoid vegetables for 5 y and be followed up to see who will develop cancer . Most of the USA 's health cl aims , permitted by the Food and Drug Administration , are not supported by RCTs . But where controlled trials of nutritional change and disease outcome have been achieved , they must be review ed very carefully . Two Cochrane review s on diet and cardiovascular disease ( CVD ) , published in the widely read British Medical Journal ( BMJ ) , were criticised after their publication and the conclusions have not been subsequently adopted by expert committees . The first of these review s was ‘ Dietary fat and prevention of CVD : a systematic review ’ . The second was ‘ Systematic review of long term effects of advice to reduce dietary salt in adults ’ . A critique of these two Cochrane review s is presented here as a contribution to our discussion of the potential of Cochrane methodology to the reliability of knowledge about diet and disease
RESULTS Our findings suggest that consumers have a relatively poor underst and ing of a healthy diet .
The literature also demonstrates that there is poor evidence on the health protective effects of single foods or nutrients .
We further show that low SES is the single consistent risk factor for not adhering to a healthy diet .
Our review of the literature on determinants demonstrates that intentions , habits , self-regulatory skills , and the social and physical environment are the most important determinants of a healthy diet , which are in turn amenable to change by intervention strategies with varying levels of effectiveness .
Educational interventions generally show a limited effect on practising a healthy diet whereas interventions targeting habitual behaviour and /or the physical environment seem more promising .
In view of the large number of people who are concerned about their diets and make attempts to change their dietary patterns , we conclude that it is crucial to gain a better underst and ing of both the automatic and environmental influences that are responsible for people not acting upon their good intentions for diet change
OBJECTIVE To discuss healthy diet from a psychological perspective by considering definitions of healthy diet in terms of consumer underst and ing ; the health effects of specific dietary elements in terms of overweight and ( chronic ) illness ; the prevalence of healthy diet ; the psychological and environmental determinants of healthy diet ; and the psychological interventions that have been design ed to promote healthy diet .