Desire for Junk Food is in Your Genes

Because it's been programmed into our genes, people prefer calorie-dense foods (Am J Clin Nutr, 2016 Aug; 104(2): 446–453), such as:

• pastries and desserts that are loaded with sugar, starch and fats,

• fried foods full of calories and advanced glycation end products (AGEs) that are known carcinogens, and

• potatoes that increase their caloric content with baking and frying.

Our hunter-gatherer ancestors spent all their waking hours scrounging for food and trying to keep from starving to death. They developed a taste for the most calorie-dense foods that satisfied best, such as honey, meats and starchy roots (the precursors of today's potatoes, yams and taro). Today, when our major nutritional problem is too much food, not too little, we still have the same taste preferences for high-density-calorie foods that are making us fat (Am J Clin Nutr, July 2005;82(1):236S-241S). We should be eating lots of vegetables and fruits that are of low-calorie density and full of water and fiber (Trends in Food Science & Technology, Feb 2015;41(2):149-160).

For example, consider these studies:

• Four-year-old children prefer calorie-dense potatoes over low-calorie vegetables such as cabbage (Appetite, Aug 2003;41(1):97-8).

• Three-year-old children prefer high-calorie-density foods such as animal products and starchy foods and tend to avoid vegetables (Acta Paediatrica, July 2005).

• Children think that the foods divided into multiple smaller meals have fewer calories than the same number of calories in one large meal (Appetite, Nov 2017;118:106-112).

• Adults markedly underestimate the caloric content of foods and choose high-calorie side dishes over those with fewer calories (J Consum Res, October 1, 2007;34(3):301–314).

• In studies lasting longer than six months, people lost three times as much weight when they ate low-energy-dense foods (low in calories and high in fiber) than in those who simply tried to restrict calories (Nutr Rev, 2001;59:247-58).

• Fruits and vegetables are full of water and fiber and therefore are almost always of low calorie density (Br J Nutr, 2001;86:265-76), and a review of the world's literature shows that people can lose weight just by increasing their intake of fruits and vegetables (J Am Diet Assoc, 1991;91:421-4).

• A review of 22 studies showed that adding high-fiber foods to a person's diet helps them lose weight (Am J Clin Nutr, 2001;73:1010-1018).

• Children prefer calorie-dense, high-fat junk foods (Nutrition Reviews, Sept 1, 1992;50(9):249–255).

• Children eat far more cereal for breakfast when sugar is added to it compared to cereals with bananas, strawberries and milk (Pediatrics, January 2011;127(1):).

• Overweight children and adolescents markedly increase their intake of calorie-dense meat, bakery products, pastas, sugar-sweetened drinks and potato chips when they eat away from home (J Amer Coll of Nutr, June 18, 2013;22(6):539-545).

Today most of us have a virtually unlimited supply of energy-dense food available, and more than 40 percent of North Americans are overweight. It is frightening to realize that the same energy-dense foods associated with obesity are also associated with increased risk for diabetes and heart disease (Circulation, July 2, 2012) and several cancers (Journal of the Academy of Nutrition and Dietetics, August 17, 2017).

My Recommendations The low-calorie-density foods that help to prevent obesity also help to prevent many diseases. A healthful diet should contain lots of vegetables, fruits, whole grains (not ground into flour), nuts, beans and other seeds and restrict energy-dense foods such as sugary drinks and foods, meats, refined grains and fried foods. Many studies show that restricting calorie-dense junk foods can help to prolong your life. See How Eating Less May Prolong Life

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