Close to 40 percent of Americans are obese - and these numbers are only increasing, according to the American Medical Association (AMA). In fact, seven states have more than a quarter of their population living with obesity.

Obesity is considered a chronic disease where your Body Mass Index (BMI), which takes into account your weight and height, is 30 or higher.

One of the biggest culprits causing obesity in the U.S.? Ultra-processed foods, proof that what we eat matters.

What Are Processed Foods?

When we talk about processed foods, there are different degrees to which food is processed. Foods can range from minimally processed to ultra-processed (highly processed). For example, if you go to the grocery store and buy an apple (a considerably healthy fruit), this could be technically classified as “processed”. That’s because as soon as that apple is harvested, it loses some of its nutrients.

And according to the U.S. Department of Agriculture (USDA), processed food is defined as any raw agricultural commodity that has been subject to washing, cleaning, milling, cutting, chopping, heating, pasteurizing, blanching, cooking, canning, freezing, drying, dehydrating, mixing, packaging or other procedures that alter the food from its natural state. This may include the addition of other ingredients to the food, such as preservatives, flavors, nutrients, and other food additives or substances approved for use in food products, such as salt, sugars, and fats.

This means even vegetables that are cleaned, cut, and then packaged would be considered processed. For example, minimally processed foods can include bagged spinach, cut, and packaged vegetables such as broccoli or carrots, and roasted nuts.

But this is not the type of processing that is causing alarming rates of obesity throughout the country. It’s the ultra-processed foods that are directly linked to obesity.

Ultra-Processed Foods

Ultra-processed foods are foods that are made from industrial ingredients that are specifically engineered to taste delicious. For example, ultra-processed foods commonly contain hydrogenated oils, high-fructose corn syrup, added artificial flavors, and emulsifiers (such as guar gum, mustard, soy, and egg lecithin). They’ll also contain a significant amount of added sugar, salt, oil, and calories - All of which contribute to obesity.

The tempting part about ultra-processed foods is that they are usually cheap and can be eaten easily, without requiring much cooking on the consumer’s end (think of foods that are frozen).

What Are Specific Examples Of Ultra-Processed Foods?

Examples of highly processed foods can include (but are not limited to):

• Ready-to-eat foods (such as crackers, cereals, granola bars, chips, cookies)
• Foods with ingredients added for flavor and texture, such as sweeteners, spices, oils, colors, and preservatives. According to the Mayo Clinic, these can include jarred pasta sauce, salad dressing, yogurt, and cake mixes
• Frozen dinners (microwaveable dinners and frozen pizzas)
• Cheese
• Milk
• Bread
• Bacon
• Butter
• Dried fruit

Does Processed Food Cause Obesity?

The National Institutes of Health (NIH) found that when people ate a diet full of ultra-processed foods, they consumed more calories and gained more weight than when they ate a minimally processed diet. The results show the importance of identifying and eating healthy foods.

These findings are the result of a 2019 study by the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) The study involved 10 men and 10 women who received either an ultra-processed diet or an unprocessed diet for two weeks, then alternated the diets for another two weeks. Each participant received three meals per day, with snacks. For example, an ultra-processed breakfast might have consisted of a bagel with cream cheese and turkey bacon. A minimally processed breakfast might have consisted of oatmeal with bananas, walnuts, and skim milk.

When participants were eating the ultra-processed foods, they ate approximately 500 calories more than when they ate the unprocessed diet and gained approximately 2 pounds.

Both diets in the study had similar amounts of calories, sugar, fat, fiber, and other nutrients.

Most of the extra calories came from carbohydrates and fats, and the ultra-processed diet also increased their sodium intake. When the participants changed to the unprocessed diet, they ate fewer calories and lost weight. Participants also reported that both diets were satisfying and tasted good, though participants tended to eat faster on the ultra-processed diet.

What Are The Effects Of Eating Processed Foods?

While carrying extra weight on our bodies can be uncomfortable, obesity can also lead to a wide range of debilitating conditions, including heart disease, hypertension, type 2 diabetes, sleep apnea, certain cancers, joint disease, and much more.

How Do You Avoid Processed Foods?

Avoiding processed foods begins with eating a healthy diet. This consists of vegetables, fruits, whole grains, fish, poultry, limited lean meats, and avoiding dairy products (or eating fat-free or low-fat dairy products). Essentially, your best bet for eating healthy is to eat real foods that are minimally processed or not processed at all.

It’s also beneficial to have a diet with limited saturated and trans fats, sodium, and added sugars. Moderation is key.

Preparing foods that are less processed and better for us requires more money and more time. And as the NIH points out, it also is not clear which aspects of the ultra-processed foods affect people’s eating behaviors and results in them gaining weight.

Of course, some people suffer from obesity due to other medical reasons not linked to processed foods. However, there is a significantly strong link between those who are obese and those who eat ultra-processed foods on a regular basis .

Check out the Obesity Code by Dr. Jason Fung, an excellent book dedicated to the topic.

Summary of the Obesity Code book

"The Obesity Code" by Dr. Jason Fung offers a groundbreaking perspective on the causes of obesity and presents a novel approach to weight loss. Dr. Fung, a nephrologist specializing in kidney disease, challenges the conventional wisdom that calorie reduction and increased exercise are the primary solutions to obesity. Instead, he delves into the hormonal mechanisms that regulate body weight, particularly focusing on the role of insulin.

Key Concepts

Obesity as a Hormonal Imbalance

Insulin's Central Role: Dr. Fung argues that obesity is primarily a result of hormonal imbalances, with insulin being the key hormone that promotes fat storage.

Insulin Resistance: Frequent spikes in insulin levels, often due to high-carbohydrate diets and constant eating, lead to insulin resistance. This condition causes the body to produce even more insulin, creating a cycle that promotes weight gain.

Flaws in the Calorie Counting Model

Not All Calories Are Equal: The book criticizes the "calories in, calories out" model, emphasizing that different foods have different hormonal effects. For example, calories from sugar can spike insulin more than calories from fats or proteins.

Metabolic Adaptation: Dr. Fung explains that the body adapts to reduced calorie intake by lowering its metabolic rate, which can stall weight loss efforts.

Impact of Diet Composition

Refined Carbohydrates and Sugars: High intake of refined carbs and sugars leads to increased insulin production. These foods are rapidly digested, causing quick spikes in blood sugar and insulin.

Healthy Fats and Proteins: Consuming fats and proteins can lead to lower insulin responses and prolonged satiety, helping to control hunger and reduce overall calorie intake.

The Benefits of Intermittent Fasting

Reducing Meal Frequency: Dr. Fung advocates for intermittent fasting as a method to lower insulin levels and improve insulin sensitivity.

Fasting Protocols: He outlines various fasting strategies, such as skipping meals or having designated fasting days, to help the body switch from burning glucose to burning stored fat.

Other Hormonal Influences

Cortisol: Stress hormones like cortisol can promote weight gain by increasing insulin levels and appetite.

Leptin and Ghrelin: These hormones regulate hunger and fullness. Insulin resistance can disrupt their normal function, leading to overeating.

Historical and Cultural Perspectives

Dietary Shifts: The book examines how dietary recommendations over the past decades, such as low-fat diets, have inadvertently increased carbohydrate consumption and obesity rates.

Cultural Eating Patterns: Dr. Fung highlights how traditional societies with periodic fasting or lower carbohydrate intake have lower obesity rates.

Practical Recommendations

Whole Foods: Emphasizes eating unprocessed foods that are lower in refined carbohydrates and sugars.

Meal Timing: Suggests incorporating periods of fasting to allow insulin levels to drop and the body to access fat stores.

Lifestyle Changes: Encourages managing stress, getting adequate sleep, and regular physical activity to support hormonal balance.