In recent years, many nutrition experts have linked the obesity epidemic to the spread of ultra-processed foods that are engineered to have a long shelf life and irresistible combinations of salt, sugar, fat and other additives.
These foods tend to make people overeat because they are full of refined carbohydrates, added sugars and fat that appeal to the human palate, experts say. Most of these foods, however, tend to lack fiber, protein, vitamins and other important nutrients. People should’t be lulled into a false sense of security if they purchase so-called healthy food that is pre-packaged. Any food that is pre-made likely has preservatives that diminish the value. Foods that are often thought to be healthy choices like cold cuts, pre-made salads, and pre-sliced fruits and veggies fall into the realm of “processed.”
Unprocessed food, on the other hand, involves raw ingredients like fresh produce, unflavored yogurt, home-cooked meat, and whole grains. But the emphasis is that the foods must not be altered in order to maintain their shelf life to be considered “whole foods.”
Researchers classify “ultra-processed” foods as items that are generally factory-made and come laden with additives and preservatives like sweeteners and thickeners. Generally, these things are packaged in plastic or cans. You’re likely to see “high fructose corn syrup” on the ingredient list of an ultra-processed food item, or perhaps some interesterified oils (replacements for trans fat) which are now widely banned.
Now a new study provides strong evidence that these foods not only tend to make people eat more, they may result in dramatic and relatively rapid weight gain and have other detrimental health effects. Beyond its link to overeating, a diet heavy in processed food is also linked with all kinds of other health problems, according to previous research. People who consume processed foods regularly are more likely to get cancer and die quicker than others.
The research, published in the journal Cell Metabolism, found that people ate significantly more calories and gained more weight when they were fed a diet that was high in ultra-processed foods like breakfast cereals, muffins, white bread, sugary yogurts, low-fat potato chips, canned foods, processed meats, fruit juices and diet beverages. These foods caused a rise in hunger hormones compared to a diet that contained mostly minimally processed foods like fresh fruits and vegetables, eggs, grilled chicken, fish and beef, and whole grains, nuts and seeds.
The subjects were recruited by scientists at the National Institutes of Health and assigned to live in a research facility for four weeks. There, they were fed both diets – a whole-foods diet or an ultra-processed one, along with snacks in each category – for two weeks each and carefully monitored. They were instructed to consume as much or as little as desired. Researchers scrutinized everything that was eaten and came away with the first hard evidence to support a long-held suspicion: heavily processed foods could be a leading factor in America’s obesity epidemic.
Volunteers’ calorie consumption and weight gain were compared when they ate a diet based on unprocessed ingredients and when they ate meals dominated by ultra-processed foods. Both daily menus had matching amounts of calories, fat, sugar, carbohydrates and salts, and diners said they were equally tasty and satisfying.
Yet the volunteers chose to consume an average of 508 additional calories per day on the ultra-processed diet. After two weeks, they weighed an average of 2 pounds more than their counterparts who had dined on unprocessed foods.
Hall said the discrepancy could be due to differences in the foods’ texture. Ultra-processed foods are generally softer, and people tend to eat soft foods quickly. That means volunteers would have swallowed more food by the time their guts were able to register their fullness and send signals to the brain that eating should stop. In future studies, he said, they’ll examine the role of texture by serving more slow-to-eat, but ultra-processed canned soups.
Whatever the explanation, participants gained an average of 2 pounds over the two weeks they ate ultra-processed foods. Luckily for them, they lost an average of 2 pounds over the two weeks they were on the unprocessed diet.
Blood sugar levels and measures of liver health remained largely the same on both diets, probably because all participants were considered healthy adults at the study’s onset, the researchers said. Interestingly, the ultra-processed diet appeared to trigger a higher expenditure of energy – but not enough to counteract the hundreds of additional calories consumed.
These findings will force scientists to rethink the complicated relationship between dietary habits and health. “I thought it was all about the nutrients,” said study leader Kevin Hall, a section chief at the National Institute of Diabetes and Digestive and Kidney Diseases, which is part of the National Institutes of Health. ”There’s something other than the sugar and fat on the food label that causes people to overeat and gain weight,” Hall said. “We don’t fully know the mechanism yet, but processed foods aren’t just innocent bystanders.”
The American diet has changed drastically over the past century. Home-grown produce and local poultry have given way to canned vegetables and deep-fried chicken tenders. Doctors have long suspected that changes in food preparation were among the key contributors to the obesity epidemic, but they’ve struggled to find ways to reverse the trend. Almost 40% of adults in America are now obese, more than double the percentage in 1980, according to the Centers for Disease Control and Prevention. The obesity rate among children has almost tripled in the same time period.
“We’re talking about foods that make up more than 50 percent of people’s diets, and they can be very attractive to people who have limited time, money, skills and access to ingredients that they can use to make meals from scratch,” he said. “For people who are working two jobs just to make ends meet and have a family to feed, a frozen pizza looks very good at the end of the day.”
But just as they may sound cheaper and easier, learning to switch over to an unprocessed diet will have a significant impact on caloric intake and weight gain. Check out our previous post on how to eat healthier, cheaper. It can be done. Below is a wonderful example of how processed foods compare to whole foods through a day.
Processed Breakfast: Honey Nut Cheerios (General Mills); whole milk (Cloverland) with NutriSource fiber; blueberry muffin (Otis Spunkmeyer); margarine (Glenview Farms)
Whole Breakfast: Greek yogurt (Fage) parfait with strawberries, bananas, walnuts (Diamond), salt and olive oil; apple slices with fresh squeezed lemon
Processed Lunch: Beef ravioli (Chef Boyardee); Parmesan cheese (Roseli); white bread (Ottenberg); margarine (Glenview Farms); diet lemonade (Crystal Light) with NutriSource fiber; oatmeal raisin cookies (Otis Spunkmeyer)
Whole Lunch: Spinach salad with chicken breast, apple slices, bulgur (Bob’s Red Mill), sunflower seeds (Nature’s Promise) and grapes; vinaigrette made with olive oil, fresh squeezed lemon juice, apple cider vinegar (Giant), ground mustard seed (McCormick), black pepper (Monarch) and salt (Monarch)
Processed Dinner: Steak (Tyson); gravy (McCormick); mashed potatoes (Basic American Foods); margarine (Glenview Farms); corn (canned, Giant); diet lemonade (Crystal Light) with NutriSource fiber; low-fat chocolate milk (Nesquik) with NutriSource fiber
Whole Dinner: Beef tender roast (Tyson); rice pilaf (basmati rice (Roland), with garlic, onions, sweet peppers and olive oil); steamed broccoli; side salad (green leaf lettuce, tomatoes, cucumbers) with balsamic vinaigrette (balsamic vinegar (Nature’s Promise); orange slices; pecans (Monarch), salt and pepper (Monarch)
Balance is always the key. Life is hectic and overwhelming. Eating processed foods makes sense sometimes. But whenever possible, and as often as possible, unprocessed is the way to keep ourselves and our family healthy and safe.