...information for health professionals

Dietary Approach - Food Optimising

Food Optimising is Slimming World’s healthy eating plan. Based on the principles of energy density and satiety, Food Optimising empowers members to make healthier food choices, satisfy their appetites and lose weight – without calorie counting or obsessive weighing and measuring it is a life-long healthy eating plan.

Food Optimising is easy to follow, focusing on three main components:

  1. The concept of Free Foods promotes consumption of plenty of low energy dense and highly satiating foods, eg poultry, fish, lean meat, pasta, grains, vegetables and fruit, which can be eaten without restriction. Members are encouraged to use these foods to satisfy their appetite while reducing overall energy intake. With Free Foods members don’t have to monitor every mouthful – so compliance is easy to establish and sustain.
  2. Healthy Extras help provide a good overall balance of nutrients in addition to those obtained from Free Foods, with particular emphasis on calcium and fibre-rich foods, eg milk, cheese, cereals and wholemeal bread.
  3. The synergy between Free Foods, Healthy Extras and Syns makes Food Optimising effective and easy to live with long term. Syns are the way members can enjoy the foods that many diets ban – without a shred of guilt! Counting Syns helps members naturally limit consumption of saturated fats, alcohol and sugar, ie those foods with a high energy density and poor ability to satisfy hunger.

The science behind Slimming World's Food Optimising

Research has shown that the nature and composition of the foods we eat, dietary macronutrients and energy density, impact on our sense of satisfaction and fullness (satiety) 1. Encouraging a higher intake of more satiating foods will limit energy intake and result in weight loss. Slimming World has been actively involved in this field of research and, along with the Scottish Office, sponsored research conducted by Dr James Stubbs at the Rowett Research Institute. There is now a robust evidence base which shows that foods higher in protein and carbohydrates are far more satiating than foods rich in fat 2 3.

Research also shows that people feel full due to the amount of food they eat, not the number of calories they take in. Choosing low energy dense foods can increase the volume of food eaten, while reducing energy intake, and thus satisfy appetite 4.

Since its inception - in 1969, Food Optimising has always successfully embraced the scientific principles of appetite regulation and energy density in a practical way to regulate energy intake, allowing members to eat unlimited amounts of highly satisfying foods, which will naturally help limit calorie intake without the chore of counting or feeling deprived.

A balanced approach

Through the structure of Free Foods, Healthy Extras and Syns, Food Optimising provides a flexible and practical weight loss plan while also encouraging a balanced approach in line with current healthy eating guidelines.

Food Optimising promotes a reduction in fat, particularly saturated fat, and the inclusion of at least five portions of fruit and vegetables per day alongside starchy carbohydrates and lean protein-rich foods to satisfy the appetite. Measured portions of fibre and calcium-rich foods are included on a daily basis.

All major food groups are encouraged in line with the Eatwell Guide1 and health notes guide members in following current Government recommendations on healthy eating.5 :

Eat well guide

Around 88% of the Eatwell Guide is made up of a combination of fruit and vegetables, starchy carbohydrates like rice, pasta and potatoes, and protein rich foods such as lean meat and fish, all of which are Free Foods within Food Optimising. A smaller section of the guide is for milk and dairy. Food Optimising classifies milk and cheese as 'Healthy Extras', and encourages those following the eating plan to enjoy daily measured portions as they are good for overall health. The smallest purple section and those foods outside of the main image are foods that are high in fat and/or sugar - these are Slimming World's controlled Syns.

Realistic and flexible, Food Optimising:

    ✓ takes into account individual needs and preferences
    ✓ adapts to all lifestyles, cultures and budgets, and is suitable for all the family
    ✓ encourages slimmers to feel free and relaxed about food, eliminating the distress caused by feelings of guilt, hunger, deprivation and loss of control
    ✓ enables members to take control of their own health and lifestyle for the long-term
    ✓ doesn't ban foods or food groups
    ✓ doesn't use expensive or specialist 'diet' products

Our research

A survey of over 2,000 people following Food Optimising showed that the programme encourages significant changes towards healthier food choices in line with current guidelines:

  • 78% now buy more fruit and vegetables
  • 74% eat less fatty food
  • 61% eat less sugary foods
  • 58% eat fewer ready meals and takeaways.

Over 80% of people following Food Optimising also reported improvements in their health. As part of a pan-European research programme, Diogenes, data shows Slimming World members who have been following Food Optimising for at least 6 months have an average percentage energy intake from carbohydrate of 51%, 21% energy intake from protein and 25% from fat.6


  1. Stubbs, J., Whybrow, S. and Lavin, J. 2010. Dietary and lifestyle measures to enhance Satiety and Weight control. Nutrition Bulletin, 35: 113-125.
  2. Weststrate, J.A., et al. 1992. Effects of nutrients on the regulation of food intake. Unilever Research: The Netherlands: Vlaardingen.
  3. Stubbs, J., Ferres, S., and Horgan, G. 2000. Energy density of foods: Effects on energy intake. Critical Reviews in Food Science and Nutrition. 40(6): p. 481-515.
  4. Ello-Martin, J.A., et al. 2007. Dietary energy density in the treatment of obesity: a year-long trial comparing 2 weight-loss diets. American Journal of Clinical Nutrition. 85(6): 1465-1477.
  5. NHS choices. The Eatwell Guide. Available from: http://www.nhs.uk/Livewell/Goodfood/Pages/the-eatwell-guide.aspx
  6. Pallister, C., Avery, A., Stubbs, J. and Lavin, J., 2009. Influence of Slimming World's lifestyle programme on diet, activity behaviour and health of participants and their families. Journal of Human Nutrition and Dietetics. 22: 351-358.

Food Optimising incorporates scientific understanding of how foods affect our appetite and translates these principles into a way of eating that is practical for use in today's world, so members can lose weight without restriction or deprivation.

Dr James Stubbs, Obesity Research Specialist

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