A leaflet entitled 'Eat more, lose weight' is published by the British Nutrition Foundation (BNF) today. The leaflet shows how slimmers can eat enough food to feel really full without consuming too many calories. The advice provided by the BNF is based on scientific evidence that lowering the energy density, or the amount of calories per gram of food consumed, can help people lose weight without feeling hungry1.
“By manipulating the energy density of the diet, you can eat much more food for fewer calories,” says Bridget Benelam, Senior Nutrition Scientist at the BNF. “For example, a home-made burger, fried chips, ketchup and a standard soft drink can provide over 1000 calories and weighs about 650g. Whereas, you can eat nearly double the amount in weight (about 1200g) for about half the calories, with a low energy density meal of, for example, soup, a low-fat sandwich, a diet soft drink and a fruit and yogurt dessert.”
What is energy density?
Energy density is the number of calories per gram of food (kcal/g). It is mainly affected by the water content, but also by the fat content of the foods.
Foods with a lower energy density include those with a high water content, such as soups and stews, foods like pasta and rice that absorb water during cooking, and foods that are naturally high in water, such as fruit and vegetables. At the other end of the scale, higher energy density foods tend to include those that are high in fat and have a low water content, for example biscuits and confectionery, fried snacks, nuts and full-fat hard cheese2.
The energy density of the diet overall is determined by the balance of higher and lower energy density foods consumed. Small amounts of food with a high energy density can be eaten as part of a low energy density diet, as long as some food with a medium energy density and plenty of food with a low energy density is consumed alongside. Also, by eating foods with a low energy density first, for example, having a salad without oily dressing or a broth-based soup, you’ll naturally feel fuller and less tempted by the high energy dense foods3, 4.
The ‘Eat more, lose weight’ leaflet shows how simple changes to your daily meals can make a significant difference to the amount of food you can consume for the same number of calories. For example, choosing fruit and cereal, instead of pastries for breakfast, soup and salad instead of burger and chips for lunch, and making a wholemeal pasta dish with a low-fat cheese sauce and extra vegetables, instead of white pasta with a standard full-fat cheese sauce for dinner, means that instead of consuming 2285 calories in 1487g of food, you can have 2321g of food for 1495 calories.
And it doesn’t mean completely changing your eating habits – favourite recipes also get a makeover in the BNF leaflet. A 400g portion of spaghetti Bolognese with standard mince, bacon and full-fat cheese contains 760 calories. However, a few simple changes can cut its calorie content by well over half. Using lean mince instead of standard mince, choosing wholemeal spaghetti, adding plenty of vegetables and using a smaller portion of a reduced-fat cheese brings the calorie content of a 400g portion down to 330 calories.
Avoiding weight-loss pitfalls
The leaflet also addresses key behaviours that can make or break attempts at weight loss. Benelam continues “It’s important to remember that we live in an ‘obesogenic’* environment’ and that we need to consider other aspects of our lifestyle, as well as the foods we eat. Things like keeping active, avoiding distractions while eating and resisting the temptation to try every dish at a buffet can really help keep weight control on track.”
*Factors tending to make people overweight
1 Benelam (2009) Satiation, satiety and their effects on eating behaviour. Nutrition Bulletin 34(2) 126-173 http://www3.interscience.wiley.com/journal/122401460/abstract
2 BNF’s ‘feed yourself fuller chart’ provides examples of foods with a high medium and low energy density. http://www.nutrition.org.uk/nutritioninthenews/fuller/feed-yourself-fuller-chart
3 Flood JE & Rolls BJ (2007) Soup preloads in a variety of forms reduce meal energy intake. Appetite 49(3) 626-34
4 Rolls BJ, Roe LS & Meengs JS (2004) Salad and satiety: Energy density and portion size of a first-course salad affect energy intake at lunch. Journal of the American Dietetic Association 104 (10) 1570-1576