FOOD SATISFACTION

October 2001

Author: Wendy Pryor

Existing evidence shows that enjoyment promotes good physical and mental health - proactively protects against ill-health - acts as an antidote to stress - counteracts negative physical and mental health

Eating as much as we like of whatever we like can be wonderfully satisfying in the short term, but it does not necessarily keep us from hunger, nor does it pave the way to optimum health. Recent scientific research is helping us to understand the factors which make food satisfying and how we can use this knowledge to assist with weight control. A variety of factors, in a complex way, produce chemical signals in the brain which tell us whether we are hungry, satisfied, enjoying or not enjoying our food. Not all kilojoules satisfy hunger in the same way, and not all individuals have the same ability to regulate their intake to match their requirements.

Although many personal, cultural and economic factors influence food selection, people mainly respond to the sensory qualities of food such as taste, aroma and texture. These properties are strongly influenced by the fat content. Fat is responsible for the smoothness of butter and cream, the moistness of cakes, the juiciness of hamburgers and the crispy textures of fried foods. The almost universal appeal of sugar & fat-rich foods holds across cultures and begins with the first taste of mother’s milk.

The pleasure response to foods may be related to opium-like molecules manufactured by the brain. This may be linked to binge eating in some people. The opiate response may relieve stress and provide comfort.

One of the problems with high fat foods is that they contain a lot of kilojoules in a small volume. It is easy to overeat fat kilojoules, firstly because they tend to taste good and they stimulate the appetite, and secondly because they don’t take up much room in the stomach compared with carbohydrates. It is much easier to binge on ice-cream than porridge. When you eat fat, the signals that tell your brain that you have had enough don’t kick in until about half an hour later. By that time you have already overeaten and are feeling sick. This is called passive over-consumption, because it can happen unintentionally.

The other problem with fats is that they don’t keep you satisfied for as long as many other foods, so you will soon want more.

Some special proteins, gums, and gels have been designed as food additive to mimic the smooth, creamy texture of fat without the extra kilojoules. They are an option if you like them.

The view that a "sweet tooth" leads to fat gain through excess sugar consumption is not strictly true. In reality, the possession of a "sweet tooth" does not correlate with body weight or shape.

The sweet taste conferred by the sugar seems to be of greater importance than sugar calories themselves. Sugar and artificial sweeteners themselves do not by themselves increase hunger, but they can increase the desirability of foods, particularly high fat ones, and increase their consumption.

The idea of the "sugar-fat see-saw" is that the more sugar you eat, the less fat you tend to eat and vice versa. Although it is very difficult to cut down dramatically on both sugar and fat, you are better off swinging to the sugar side in terms of weight control. A good strategy is to try not to eat too much of foods containing high levels of both fat and sugar, otherwise you will have a very addictive way to consume lots of kilojoules with only fleeting sensory satisfaction and little impact on hunger.

Physical properties which generally increase food satisfaction include high fibre content, viscosity, the ability to soak up fluid in the stomach (cheese, porridge, potatoes) and large particle size (eg whole grains).

The bulk of a food and its viscosity (thickness) affects stretching and emptying of the stomach as well as our psychological perception of how much we have eaten. A bulky food like popcorn fills the stomach without taking in a lot of calories.

Researchers at the University of Sydney have developed the "Satiety Index", which is a score to rate foods according to how well they stave off hunger between meals.

Potatoes are most satisfying food tested so far, but French fries don’t score well! Apples, oranges, porridge and fish score highly but, the tastiest foods - those high in sugar and fat, like cakes and Mars Bars – do not provide lasting satisfaction. See the details at http://www.diabetesnet.com/index.html.

Chemical substances in foods also make a difference. Beans and lentils, for example, contain anti-nutrients which delay their absorption so they make you feel full for longer, and potatoes contain a protein which stimulates a brain chemical to tell us we are satisfied.

Enjoyment promotes good physical and mental health, so it is good to strive for pleasure in eating as in any other aspect of our lives. Here are a few suggestions which may help to get the most satisfaction from food without excessive kilojoules:

• Use fresh high quality ingredients, carefully seasoned and cooked with minimal fat to achieve flavour, aroma, texture and eye appeal .
• Eat slowly to maximise sensory satisfaction and make the most of every mouthful.
• Enjoy a little sugar, but watch out for sweet foods packed with fat.
• Allocate portion sizes that will satisfy but not overfill.
• Eat a varied diet with an emphasis on foods with a high satiety index.
• Be free to enjoy your food as one of life's great pleasures. Guilt does not satisfy.