Dietary energy density (DED) is defined as the amount of available energy per unit of weight in the diet. It is generally expressed as kJ/g. Experimental studies in human subjects and a recent systematic review have shown that the consumption of high-energy-dense diets may lead to increased energy intake and weight gain, and evidence has been accumulating for an association between lower DED and better nutritional quality of the diet.
In Swedish children and teenagers, it was found that low-energy-density diets contained higher amounts of protein, carbohydrates, fibre and most of the micronutrients and lower amounts of energy, fats and sucrose. In American children aged 2–8 years the associations between DED and food intakes and some dietary characteristics were examined. It was found that young children with lower DED consumed more food (g) and less energy, more portions of fruit and vegetables, had a lower energy intake from fat and consumed less added sugar than those with higher DED. In studies of adults, the intakes of protein, carbohydrates and dietary fibre decreased with increasing DED and the intakes of energy and fats and added sugar increased with increasing DED. Furthermore, more favourable eating patterns, e.g. eating patterns more in line with food-based dietary guidelines, consuming more fruit and vegetables and consuming less low-nutrient-dense foods, have also been reported for adults with lower DED, while better adherence to food-based dietary guidelines has been reported in children and teenagers with lower DED. It has also been proposed that DED could be used as a marker of the nutritional quality of the diet.
Diet is believed to play a role in cancer risk. Current research shows that an estimated 30% of cancers could be prevented through nutritional modifications. While there is a proven link between obesity and certain types of cancer, less is known about how the ratio of energy to food weight, otherwise known as dietary energy density (DED), contributes to cancer risk. To find out, researchers looked at DED in the diets of post-menopausal women and discovered that consuming high DED foods was tied to a 10% increase in obesity-related cancer among normal weight women. Their findings are published in the Journal of the Academy of Nutrition and Dietetics.
It has been estimated that 30–40 percent of all cancers can be prevented by lifestyle and dietary measures alone. Obesity, nutrient sparse foods such as concentrated sugars and refined flour products that contribute to impaired glucose metabolism (which leads to diabetes), low fiber intake, consumption of red meat, and imbalance of omega 3 and omega 6 fats all contribute to excess cancer risk. Intake of flax seed, especially its lignan fraction, and abundant portions of fruits and vegetables will lower cancer risk. Allium and cruciferous vegetables are especially beneficial, with broccoli sprouts being the densest source of sulforophane. Protective elements in a cancer prevention diet include selenium, folic acid, vitamin B-12, vitamin D, chlorophyll, and antioxidants such as the carotenoids (α-carotene, β-carotene, lycopene, lutein, cryptoxanthin). Ascorbic acid has limited benefits orally, but could be very beneficial intravenously. Supplementary use of oral digestive enzymes and probiotics also has merit as anticancer dietary measures. When a diet is compiled according to the guidelines here it is likely that there would be at least a 60–70 percent decrease in breast, colorectal, and prostate cancers, and even a 40–50 percent decrease in lung cancer, along with similar reductions in cancers at other sites. Such a diet would be conducive to preventing cancer and would favor recovery from cancer as well.
Credit: National Institute of Health
Academy of Nutrition and Dietetics