Healthy eating: clarifying advice about fruit and vegetablesBMJ 1995; 310 doi: https://doi.org/10.1136/bmj.310.6992.1453 (Published 03 June 1995) Cite this as: BMJ 1995;310:1453
- Carol Williams, visiting lecturera
- a Human Nutrition Unit, Department of Public Health and Policy, London School of Hygiene and Tropical Medicine, London WC1H 0BT
- Accepted 7 March 1995
Consumers need health information which is clear and unambiguous. Advice to “eat more fruit and vegetables” gives consumers no guidance on the quantities involved. Popular advice is to eat “five portions a day.” This paper provides a rationale for determining which foods are included within this advice—for example, processed foods such as baked beans are but potatoes and nuts should not be. It also describes how much of the most commonly consumed fruit and vegetables constitutes a “portion.” A bowlful of salad, for example, is needed to make up a portion but an apple or banana on its own will count.
The government's nutrition task force recently decided that it wanted to provide consumers with information on the amounts of fruit and vegetables, bread and cereals, and fish recommended for a healthy diet. It set up a subgroup to advise on simple and practical messages on the consumption of these foods. This paper reflects the conclusions of that subgroup on fruit and vegetables.
Until recently health advice about fruit and vegetables from government organisations has tended simply to recommend eating “more.” This advice is open to different interpretations concerning which fruit and vegetables are included (does it include potatoes or fruit juice?) and the amounts.
No universally accepted convention exists on which foods should be included in health advice on fruit and vegetables.1 When different definitions are used misleading conclusions can be drawn about current levels of fruit and vegetable consumption, and the interpretation of diretary surveys can be conflicting. Lack of clarity over the status of the more controversial foods such as dried fruit or pulses can lead to confusion and uncertainty among consumers. Disagreement among academics and health professionals over these issues lends further weight to the public perception that nutrition experts “never agree.”
Advice which simply recommends eating “more” gives consumers no indication of how much is reasonable and allows complacency about present levels of consumption. A study of fruit and vegetable consumption in Scotland found that among respondents whose intake of fruit and vegetables was low (less than two portions a day) 55% thought that they were eating enough and already eating “more.”2 In England, the nutrition task force noted that “even where consumers are aware of the main healthy eating messages they are often unsure how to translate these into appropriate food choices.”3 Providing practical quantified advice onhealthy intakes of foods may help to solve this problem.
National quantified targets
Before the Committee on the Medical Aspects of Food Policy's cardiovascular review group published its report in November 19944 there were no national numerical goals for fruit and vegetable consumption for England, Wales, and Northern Ireland. The Scottish diet report in 1993 recommended that Scotland's population should eat an average of at least 400 g of fruit and vegetables (excluding potatoes) a day.5 This is consistent with the lower limit population goal for fruit and vegetable consumption contained in the World Health Organisation's report Diet, Nutrition and the Prevention of Chronic Diseases.6 The cardiovascular review group recommends a 50% increase in the mean population intake of fruit and vegetables.
Estimates of current intakes of fruit and vegetables in Britain vary. The National Food Survey estimated mean consumption of fruit and vegetables to be around 275 g per person a day,7 but this excludes foods eaten outside the home and was based on households so that the average includes the amounts eaten by small children. It also uses the weight of foods bought, not eaten so includes the weight of peel, core, and discarded outer leaves etc. I have adjusted the figures from the National Food Survey to take account of this using factors for edible proportions,8 and my estimate is that the mean weight of fruit and vegetables consumed is around 240 g/day. Data from the Dietary and Nutritional Survey of British Adults (which recorded amounts actually consumed and includes food eaten outside the home) indicate a mean adult consumption of fruit and vegetables of around 250 g a day. On these figures, a 50% increase in consumption would raise mean intakes to around 375 g and purchases to around 435 g a day. These figures are lower, but similar to the 400 g target of the Scottish diet report and the World Health Organisation report.
Practical advice for consumers
What then is the practical interpretation of this 400 g target? Popular health magazines have advised consumers to eat “at least five portions of fruit and vegetables a day” based on “decent sized” portions of around 80 g.10 11 12 13 Public awareness of the “at least five” message is growing in Britain and it is now widely used in the popular media. It has been used by the Europe Against Cancer programme14 and is the basis of several commercial promotions.15 16 The concept of “five a day for health” is also well established in the United States.17 18
But is five correct? There are currently no accurate figures available on the number of servings of fruit and vegetables consumed in Britain. Comparison of mean intakes from the adult's survey19 with data on average portion sizes as published by the Ministry of Agriculture, Fisheries, and Food (table I)20 suggests that most people, particularly those in lower socioeconomic groups, are eating fewer than five portions a day. Even if there was agreement on what amounts constitute a portion, we do not know whether the “eat five” message is effective at achieving the desired dietary changes.
In the absence of research into the effectiveness of particular quantified advice on fruit and vegetable consumption, any recommendation should encourage greater consumption but not be so ambitious that it puts people off. Consistency is also important in fostering confidence. Eating five portions a day clearly represents an increase in consumption for most of the population, and there is currently no evidence to suggest that it is either inappropriate or ineffective in achieving levels of desired dietary change. On the basis of these considerations the nutrition task force subgroup advises people to aim to eat at least five portions/servings of fruit and vegetables a day.
Which foods are included?
Different types of fruit and vegetables have differing nutritional attributes—for example, avocado pear is an excellent source of vitamin E but is also high in fat. Ideally, consumers need to be encouraged to eat fruits and vegetables with a range of nutritional characteristics. This can be achieved by emphasising variety—for example, “try to eat five different fruits and vegetables.” This avoids the need to complicate advice further and should help to maximise levels of intake. Agreement is also needed on the place of more controversial foods. The subgroup believes that fruit juice, baked beans and other pulses, dried fruit, and fruit and vegetables which are frozen, canned, or used as a main ingredient in recipes or composite foods should be included but that potatoes and nuts should be excluded (table II).
How much in a portion?
Whether advice to “eat five a day” should refer to the number of occasions of eating fruit and vegetables or the number of portions is uncertain. To achieve the kind of dietary changes proposed in health strategies such as the Health of the Nation and The Scottish Diet advice needs to promote consumption of five “decent sized” servings or portions. A couple of slices of tomato in a sandwich or a few mushrooms in a chicken and mushroom pie should not count.
Nutrition information which uses a mean portion size of around 80 g as a decent sized portion ties in well with average serving sizes used by households in Britain.20 The main area of discrepancy is with salad foods: consumers and caterers should be told that it is necessary to eat a “bowlful” of salad to count as one portion.
Table III uses this approach to show amounts which constitute a “portion” of fruit and vegetables. Supporting advice should explain that serving size should reflect age, sex, and activity and that active young men would be expected to eat larger portions. Similarly, small children can still aim to “eat at least five” but their portions may be smaller.
I thank the policy unit of the Consumers' Association for supporting initial development work for this paper and for comments received from interested parties, particularly the Department of Health.
A more detailed list is available on request for use in preparing photographs and illustrations of portion sizes and for interpreting dietary surveys.
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