Food & Health
• Main health promotion messages
What is a healthy diet?
What is a healthy diet?
For this review the term healthy eating is based on the Government’s eight guidelines for a healthy diet which are listed below:
- Enjoy your food
- Eat a variety of different foods
- Eat the right amount to be a healthy weight
- Eat plenty of foods rich in starch and fiber
- Don’t eat too much fat
- Don’t eat sugary foods too often
- Look after the vitamins and minerals in your food
- If you drink alcohol, keep within sensible limits.
The Balance of Good Health produced by the Health Education Authority is based on the Government’s guidelines and aims to help people understand and enjoy healthy eating. See Appendix 1 for copy of the Balance of Good Health.
Benefits of eating a healthy diet
Healthy eating helps reduce the risk of developing many conditions such as heart disease, cancer, constipation, obesity and tooth decay. Also eating a good variety and balance of foods ensures an adequate intake of nutrients, which prevents various deficiency illnesses such as anemia and maintains health.
Statistics specifically related to obesity and overweight indicate that 13% of men and 16% of women are now obese, and about half the adult population are either overweight or obese.
There are clear links between Body Mass Index (BMI) used as a classification of overweight and obesity, and social class, particularly for women. Women in social classes IV and V tend to have a higher BMI than women in social classes I and II. 23% of women in social classes IV and V have a BMI greater than 30 compared to 11% in social classes I and II identifying the extent of obesity in these groups.
People who are obese (Body Mass Index, BMI>30) or overweight (BMI>25) have a higher risk of disease including coronary heart disease, diabetes, hypercholesterolaemia, hypertension, bone and joint disorders. The risk of disease increases with increasing BMI.
Men and women with a waist circumference greater than 94cm and 80cm respectively are at increased risk and men and women with a waist circumference greater than 102cm and 88cm are at substantial risk.
Intra-abdominal obesity assessed by GHR (waist circumference divided by height) or WHR (waist hip ratio), carries a greater risk of cardiovascular disease, hypertension and non- insulin dependent diabetes than other types of obesity (eg hips, thighs ,peripheral areas)
In Wales 55.2% of adults are overweight or obese with a Body Mass Index (BMI) of 25 or greater.
Research has also demonstrated that increases in BMI occur at specific life stages. For women the greatest increase occurs between 15 – 19 years and for men the greatest increase is during the late 30’s. This may suggest a targetted approach to prevention.
There is also good evidence that the risks of obesity in people of Asian origin are greater than in other groups. This group also tend to have a higher waist – hip ratio for a given BMI, but the reasons for these differences are not known (Department of Health: 1995).
There are specific recommendations to:
- Reduce the average percentage of food energy derived from saturated fat by at least 35% from 17% to no more than 11%
- Reduce the percentage of food energy derived from total fat by at least 12% from about 40% to no more than 35%
- Reduce the average percentage of men and women aged 16 – 64 who are obese by at least 25% for men and at least 33% for women from 8% to 6% for men and 12% to 8% for women
An additional implication of achieving these targets is to increase the consumption of starchy foods and fruit and vegetables.
Healthy eating interventions targeted at a range of population groups in a range of settings are effective in achieving dietary change. The characteristics associated with effective interventions were;
- A focus on diet or diet and exercise only
- A behaviourally based -theoretical model.
- A degree of personalisation of the intervention, usually by a health professional.
- Active involvement of influential people eg family, community leaders.
- Changes in local environment and policy for long-term change.
• Treatment of Obesity
Interventions to reduce sedentary behaviour in children in combination with moderate changes in diet and lifestyle which avoid restrictive diets and exercise programmes are effective at reducing obesity in children.
Interventions to reduce obesity in adults which include more than one approach in combination (behavioural therapy, exercise, diet modification) are more likely to be effective than single interventions (minimum 1 year treatment and follow up).
Clinical guidelines for the prevention, assessment and management of obesity are available and should form the basis of weight management interventions.
Very low calorie Diets (800 kcal/d; 3530kj/d or less) can be effective at promoting significant short-term weight loss in obese patients. However, long-term maintenance of weight loss suggests no other benefit over other dietary treatments. Incorporation of behavioural modification and exercise in treatment programmes may improve maintenance.
Weight loss programmes should include mechanisms for longer-term follow up and maintenance to minimize regain.
Combined treatment and maintenance programmes including behavioural therapy, relapse prevention and telephone or mail contact are effective at promoting weight maintenance.
The evidence regarding the negative effects of weight cycling (repeated loss and gain of weight) is not sufficient to override the potential benefits to obese patients of weight loss. However, consideration should be given to weight maintenance as a component of weight loss programmes.
• Research demonstrating effectiveness of health promotion interventions:
Both the Health Education Authority and the Dutch centre for Health Promotion and Health Education have recently conducted a comprehensive effectiveness review of nutrition interventions, (Andrien M: 1994, Health Education Authority: 1997) The main findings of these reviews showed:
Overall, studies which were of good quality and included some dietary outcome measure showed a beneficial intervention effect. The most frequently measured outcome was dietary fat, and the review found that this was reduced by 1 to 4 % of energy intake in long term interventions in the general population.
Fewer than half the studies reviewed measured blood cholesterol. Good quality studies carried out in schools, workplaces and primary care settings, found a reduction in blood cholesterol ranging from 2 to 10%. The majority of good quality studies of community based interventions showed no effect on blood cholesterol. The greatest reduction in fat intake (10 to 16% of energy) and blood cholesterol (7 to 10%) were seen in highly motivated individuals taking part in intensive programmes.
Interventions in supermarket and catering settings showed at least a short-term effect on food purchases, increasing the total market share of promoted food items to between 1 and 4%. Altering the composition of food, instead of actively promoting healthier items, decreased the fat content of catered meals by 6 to 12% of energy intake.
•Characteristics of effective healthy eating interventions:
School-based interventions were assessed as part of a systematic review. Twenty-one studies were included of which seven were considered to be of good quality. The range of interventions used centred on traditional classroom based education supplemented by one or more other components e.g. parental/home involvement, modification of school meal system, health screening including cholesterol testing. Four of the seven good quality studies and 10 of the total showed a positive effect on either dietary intake or blood cholesterol.
A number of reviews of school-based nutrition education programmes have drawn similar conclusions on the characteristics of successful programmes these include the following:
- Effective programmes are behaviourally focused.
- Interventions are more effective when derived from appropriate theory and research
- The greater the level intensity of the programme the greater the effect.
- Family involvement is beneficial for younger children.
- Self evaluation/assessment and feedback is an effective component of programmes for older children.
- Interventions in the wider school environment should form a component of the programme.
- Interventions in the wider community can enhance school programmes.
Interventions set in the Workplace using diet only and multi-factoral approaches have a positive approaches have a positive effect on reducing dietary fat intake (1%-16% of energy) and blood cholesterol levels (2.5%-10%).
• Primary care and the community
- Focus tended to be on diet only or diet and exercise
- More effective interventions are based on theories of behaviour change which may encourage goal setting
- The degree of personal contact with individuals, small groups, family involvement and scope for personalisation enhances effectiveness
- Feedback on behaviour change and changes in risk factors were successful
- Promotion of changes in local environment e.g. catering sector
- Multiple contacts over long periods of time
- Promotion of a healthy nutritional environment
• Supermarkets and catering settings
- Menu or shelf signs identifying healthier choices reinforced with more detailed leaflets and active marketing
- Manipulation of availability and accessibility of healthier choices resulting in short term changes in meal choice
- Recipe changes to improve nutritional content without the customer knowledge changes the content of specific meals for the duration of the change
In conclusion, interventions in a variety of settings and with a variety of populations should be implemented in view of the multiple benefits of dietary changes on a variety of chronic conditions.
• Nutrition interventions with specific groups:
Additional effectiveness reviews have been produced by the HEA which examine healthy eating interventions in target populations of older people, infants 0 to 1 year, children 1 to 5, years pregnant women and women of childbearing age and people from minority ethnic groups (Health Education Authority: 1997,1998)
Traditional group based teaching has a positive impact on knowledge and/or self reported dietary behaviour in a number of population groups including the under 5’s, pregnant women and elderly people in community settings.
• 0 to 1 year
Promotion of breast feeding is enhanced by interventions which are:
- Aimed at mothers during the pre and post natal periods
- Educational in design
- Based on pre-determined issues
- One to one sessions for women from low income and minority ethnic groups are more successful at persuading women to breastfeed
- Group sessions improve the duration of breast- feeding in these groups
- Based in hospital or clinic settings
- Personalised or “needs focused” programmes are successful at initiating breast feeding but not duration
- Modification of the discharge pack increases duration of breast- feeding
Promotion of good dietary practices in weaning and post-weaning are enhanced by interventions which offer:
- Post-natal support from a lactation counselor
- Modification of the contents of commercial packs given on discharge
- Regular maternal contact with peer supporters
• 1 to 5 years
- Increasing knowledge about healthy eating is improved using traditional, video or computer-based teaching methods
- Involving parents
- Using the school setting
- Using food tasting as part of an intervention which used behaviour modification as a technique
- One to one counselling of mothers with pre-school children addressing specific needs
- Giving food vouchers in addition to one to one counselling
- Producing newsletters and running nutrition workshops for carers
• Pregnant women and women of childbearing years
- Community-based programmes can be effective in the short term for women of childbearing age
- Each programme includes an educational component
- Interventions can be used to promote healthier eating, particularly a reduction in dietary fat intake for the duration of the intervention.
• Elderly people living in the community
- Targeting individuals with an inadequate diet using a motivational, group-led approach in the community meal setting
- Community organisation using social events, favourable bread pricing, media coverage and social marketing
- Promoting fruit and vegetable consumption through garden boxes, gardening and nutrition classes may have some success.
- Feedback and goal-oriented interventions may lead to improved diet
• Minority ethnic groups
- Food supplementation or fortification in a clinic setting
- School –based classroom healthy interventions
• Evidence of effectiveness of nutrition training and projects in areas of high health need
• Nutrition Training
Members of the primary health care team have a significant role to play in disseminating advice about food and health. However, reports have suggested that there is a lack of nutrition knowledge amongst members of the primary health care team. Studies suggest that knowledge can be increased through training programmes (Kyle: 1993, Cadman and Wiles: 1996).
• Projects in areas of high health need
There is a plethora of evidence which demonstrates the links between poverty, poor health and poor diet. Any project which aims to address these issues would appear to be a useful way of improving nutrition and health status within the population.
Various community food initiatives have been developed throughout the United Kingdom. These include the establishment of food co-operatives, projects to enhance cooking skills and the development of nutrition education programmes amongst low-income groups. There is little research, which establishes the effectiveness of projects, which are aimed at groups in areas of high health need.
However, many projects are evaluated at a local level. Examples of some of these projects are included here and the reports provide a description of the evaluation methods used.
Friends with Food project :
Friends with Food was an innovative nutrition education programme aimed at low-income families in the UK. This pilot scheme was implemented in an urban area of a town in the North of England and was subjected to extensive evaluation from 1990 – 1994. The Health Education Authority funded the project. From the findings it was possible to achieve both significant increases in nutritional knowledge and potentially beneficial changes in the dietary practices of limited income families even though they are traditionally considered ‘hard to reach’.
The best approach for this type of nutrition education appears to be one in which guided ‘hands on’ food preparation / cooking sessions allow participants to acquire knowledge and skills needed to translate theoretical nutrition messages into practice, using examples relevant to their cultural, social and economic circumstances. (Huddersfield NHS Trust, 1990-1994)
Get Cooking! Is a national initiative with the aim of promoting cooking in an informal and enjoyable way. Two pilot projects were set up on the Bournville Estate in Weston – Super – Mare based on the underpinning principles of the national project, but adapted for the specific needs of the locality. The aim of the project to develop and enhance cooking skills of the participants was achieved. In addition many other outcomes were achieved. (Beavington and Thomas, 1996)
Food Co-ops :
A food co-op is a group of people buying food in bulk at wholesale or discount prices. By pooling, a bulk purchase can be made and a discount obtained. The savings are then passed on equally to everyone involved. This means that people on a low income are more likely to have access to good quality, and healthy foods more easily. Any money saved can be spent on foods that could not be afforded otherwise, like extra fruit and vegetables. (Bolton Food Co-ops)
• Web sites
- British Dietetic Association – http://www.bda.uk.com
- Health Education Authority (folic acid) – http://www.hea.org.uk
- British Nutrition Foundation – http://www.nutrition.org.uk
- Nutrition and Food Science Journal – http://www.mcb.co.uk/nfs.htm
- Think Fast – Healthier Choices for Fast Food – http://www.thinkfast.co.uk/launch.html
Andrien M. (1994), A review of the effectiveness of Health Promotion
and Health Education. Dutch Centre for Health Promotion and Health Education
Beavington J. and Thomas L. (1996), Get Cooking! Report of a pilot project to develop and enhance cooking skills, Bristol Area Specialist Health Promotion Service
Bolton Food Co-ops, Start your own Food Co-op: It’s easy, North Western
Regional Health Authority (available from Lindsey Thomas on 0117 9758032).
Cadman L. and Wiles R. (1996) Nutrition advice in primary care: evaluation of practice nurse training programmes. Journal of Human Nutrition and Dietetics (1996), 9. 147-156.
Department of Health, (1991) Dietary reference values for Food Energy and Nutrients for the United Kingdom, London: HMSO
Department of Health, (1993), Health of the Nation, key area handbook, Coronary Heart Disease and Stroke.
Department of Health, (1995) Obesity – Reversing the Increasing Problem of Obesity in England
Effective Health Care, (1997), The prevention and treatment of obesity.
Health Education Authority, (1990) Eight Guidelines for a Healthy Diet.
Health Education Authority (1997) Summary bulletin 6 – Health promotion interventions to promote healthy eating in the general population
Health Education Authority (1998) Summary bulletin 9 – Health promotion interventions to promote healthy feeding of infants under one year of age
Health Education Authority (1998) Summary bulletin 10 – Effectiveness of interventions to promote healthy eating in pre-school children aged 1-5 years
Health Education Authority (1998) Summary bulletin 11 – Effectiveness of interventions to promote healthy eating in pregnant women and women of childbearing age
Health Education Authority (1998) Summary bulletin 8 – Effectiveness of interventions to promote healthy eating in elderly people living in the community
Health Education Authority (1998) Summary bulletin 12 – Effectiveness of interventions to promote healthy eating in people from ethnic minority groups
Health Evidence Bulletins Wales (1999) Healthy living chapter 3 – Food and Health (including Overweight and Obesity)
Huddersfield NHS Trust Health Promotion Unit, The Development of a Nutrition Education Programme for Low Income Groups 1990 – 1994 (available from Lindsey Thomas on 0117 9758032).
Kyle A. (1993) Are practice nurses an effective means of delivering dietary advice as part of health promotion in primary care? Evaluation of practice nurse training in Somerset. Journal of Human Nutrition and Dietetics, (1993), 6, 149-162.