To lose weight and get smaller you need to create an energy deficit; you must take in less energy that you expend. In physics terms 2llb of fat is equal to a deficit of 500 calories a day. At first this may sound like a lot, but if you are eating the right foods you can still undercut and not go hungry. Similar to the glycaemic index experts at the University of Sydney have come up with the satiety index, a list of the top 10 foods that fill you up the most. As with any survey or nutritional advice of this kind it’s important to remember that nutrition is a field in which there are many contradictions and contentious issues. The key is to keep it as natural as possible, eat small meals often and exercise in a structured and focused way. The list below can help eaters choose foods wisely in order to minimise calorific intake while staying full. There are also lots of useful tips on our nutrition fact sheet. You can download this for free from our “Knowledge” page.
What is the ‘Satiety Index’? At its simplest, the satiety index, is a measure of how long a particular food will stop you from feeling hungry. It was first developed by Dr Susanne Holt back in 1995. Holt and her colleagues fed volunteers 240 calorie portions of a wide variety of different foods in an attempt to discover which would be the most filling. The foods were served from under a hood to minimize the influence of appearance, and, if possible, they were served at the same temperature and in the same size chunks.
After eating, the volunteers told the researchers what their appetite ratings were, but they were not allowed anything else for the next two hours. Then, after two hours, they were allowed to eat from a small buffet where the scientists measured how much they nibbled from a variety of other foods. Their consumption was closely monitored, and every 15 minutes they were questioned about their hunger to see if their subjective impression of satisfaction matched their eating behaviour. Using this information, Holt and her colleagues were able to put together the satiety index . White bread was taken as the baseline of 100 and other foods were scored on their comparative ability to satisfy hunger. Foods scoring higher than 100 were more satisfying than white bread whereas those scoring under 100 were less satisfying.
So, what are the top ten most filling foods?
1. Potatoes (323% more satisfying than white bread)
2. Fish (225%)
3. Porridge/Oats/Oatmeal (209%)
4. Apples (197%) and Oranges (202%)
5. Wholewheat Pasta (188%)
6. Beef (176%)
7. Beans (168%)
8. Grapes (162%)
9. Wholemeal Bread (157%)
10. Popcorn (154%)
What Makes These Foods So Filling?
Protein: Protein has been shown by numerous studies to be one of the most satiating nutrients. Scientists at the National Institute for Medical Research in France have recently discovered that during its digestion, glucose is produced in the small intestine. The liver senses this and relays a message to the brain to slow down or stop eating — an effect that lasts well after the food has been swallowed.
Fibre: Unlike protein, fibre promotes satiety by slowing the rate at which the food is actually digested. It also triggers stretch receptors in the stomach which automatically sends a signal to the brain to stop eating.
Water Content: Foods with a high fluid content such as apples, oranges and grapes also trigger the stretch receptors however, they are mostly made of water and sugars therefore the speed at which they are digested means that, unlike most other high S.I foods initial feelings of fullness can drop of fairly quickly. “This is why” explains Dr Holt “ that when a dieter eats a meal based on several pieces of fruit and some rice cakes (also very quick to digest) they invariably feel ravenous a few hours later. Despite the meal being low in fat and calories it isn’t at all filling. Far better to eat a wholesome salad sandwich on wholegrain bread with some lean protein like tuna or beef and an apple. This kind of meal can keep hunger at bay for a very long time.”
Volume: Another thing that increases a food’s S.I rating is its bulk. Popcorn for example only contains 55 calories per cup but it takes up a lot of space in the stomach helping to create the feelings of fullness. Fat on the other hand is the exact opposite. At 9 Kcal per gram fat is the most energy dense nutrient we can eat. Just one tablespoon of clotted cream has almost four times more calories than a whole cup of popcorn and yet it takes up far less space in the stomach making it incredibly easy to over consume. Fat greatly enhances the taste of a food too, another reason why we find it so easy to over consume.
Chemical Compounds: The chemical constituents of foods can also make a difference to satiety. Beans and lentils, for example, contain anti-nutrients which delay their absorption. Another reason why they have a tendency to make you feel full for longer.
Chewing: Chewing promotes satiety, partly because it slows down eating but also because it encourages the release of enzymes that register fullness in the brain.