You’ve just finished a delicious meal at a restaurant and you are stuffed (Thanksgiving full!)—you couldn’t possibly eat another bite. And then the waiter brings by the dessert tray and you decide you have to have the cheesecake. You sit down to watch TV and grab a bag of chips and start munching on them since you typically eat a snack when you watch TV and before you know it, the bag is empty. You ate way more than you planned on and more than you were hungry for. In both of these scenarios, you were overeating. We have all been in situations like these. The definition of overeating in the Cambridge Dictionary is “the action of eating more food than your body needs, especially so that you feel uncomfortably full”. Overeating on a regular basis will lead to weight gain, which typically involves increasing the amount of body fat a person has.
According to the Centers for Disease Control and Prevention (CDC), in 2017-2018, about 73% of adults and had overweight or obesity which has increased from about 65% in 1999-2000. This is a huge problem since obesity-related conditions such as heart disease, stroke, type 2 diabetes and certain types of cancer are some of the leading causes of preventable, early deaths in adults.
So why are so many adults gaining weight? A researcher at the National Institutes of Health named Kevin Hall is trying to answer this question by looking at the characteristics of the current food environment that regulate appetite and cause people to overeat. Volunteers for Dr. Hall’s research spent several weeks living in a lab in 2019 so that Dr. Hall could accurately measure what people ate and how many calories they burned. Participants were offered mostly unprocessed foods (vegetables, fruits, beans, nuts, seeds, poultry, seafood, meats, eggs, milk, unflavored yogurt, oats, rice, unsweetened shredded wheat) for 2 weeks and then ultra-processed foods (sugary drinks, chips, ice cream, chocolate, packaged sweets, flavored yogurts, breakfast cereals, frozen pizza, fish sticks, chicken nuggets, hot dogs, instant soups) for 2 weeks. During both time periods participants were told to eat as much or as little of the food as they wanted. On average, people ate 500 more calories a day when eating the ultra-processed foods compared to the unprocessed foods, which led them to gain weight and body fat. The ultra-processed foods had a higher caloric density than the unprocessed foods, which means that the ultra-processed foods have more calories per bite of food. For example, 1/2 square of dark chocolate has about 33 calories while one baby carrot has 4 calories. This would help explain why the people who were eating the ultra-processed foods ate more calories.
Our bodies are designed to store body fat and defend against efforts to decrease the amount of body fat we have. In hunter-gatherer societies (about 12,000 years ago), having extra body fat could mean the difference between living and dying. In today’s society where food is more available and plentiful we don’t need to have excess body fat to ensure we survive during times of famine.
About 50 years ago, food companies started doing research to figure out how to entice people to eat more of the food they produced. Food companies sought to take advantage of our natural urge to keep eating by manipulating the amounts of sugar, fat and salt in their products. They also focused on other factors to boost sales such as increased variety of flavors, ease of eating the foods, encouraging snacking, keeping foods low cost, and advertising. The end result is to try and get people hooked on eating their food products.
Sugar: The food industry came up with the term “bliss point” to describe the perfect amount of sugar (not too little and not too much) in a drink or food.
Fat: Many snack foods like potato chips have 50% of the calories coming from fat. This creates a melt-in-your-mouth sensation so you often don’t need to chew the foods much.
Salt: Having a lot of salt in foods, especially on the surface of the food, is very appealing since salt provides a burst in flavor as it touches the tongue.
Fat plus carbs: Foods that contain both high amounts of fat and refined carbohydrates like ice cream, french fries, pizza and cookies are the foods people find the most irresistible.
Variety: Eating a variety of food increases the chances of getting all the nutrients we need. However, having access to a variety of foods can also compel people to eat more. When people were served sandwiches with 4 different fillings, they ate a third more than when they were served sandwiches with only one filling.
Ease of eating: Ultra-processed foods usually take less time to eat than unprocessed foods which can result in eating more of the ultra-processed foods. Unprocessed foods often need to be chewed more due to having more intact fiber and being crunchier.
Encouraging snacking: The food industry has created many products to encourage us to snack during the day. These food products are convenient to eat while doing something else (such as watching TV or working on a computer) which can cause our brains to ignore signals from our stomachs that we are getting full.
Low cost: Food companies try to make products as cheaply as possible in order to increase their profits and to sell more of their product to budget conscious consumers. They will often use flavors that mimic the taste and smell of real foods which helps keep their costs low.
Advertising: TV ads for food products will often focus on creating strong food memories by showing their product as they are triggering our emotions with the content of the commercial. The idea is to influence our food preferences to increase consumption of ultra-processed foods.
Information compiled from:
“Why We Overeat” by Bonnie Liebman Nutrition Action Healthletter April 2021