Junk food is made to taste good, not satisfy

Q: Can you please talk about what makes something count as “junk food?” My diet has been less than stellar during the pandemic, and not only did I gain weight, but I just got the news that I have prediabetes. Specifics about how those kinds of food are bad for your health would help a lot.

A: We have often addressed the adverse health effects of eating a diet that is high in fast foods and snack foods. But with high blood sugar, elevated blood pressure, excess weight, surplus abdominal body fat and abnormal blood lipid levels becoming a not-so-silent epidemic here in the United States, your request for a closer look at these foods is timely.

When someone talks about fast food or junk food, they're often referring to what have come to be known as ultra-processed foods. These are foods so radically changed from their original state that they neither look nor taste like the ingredients from which they are made. This is achieved both through how these foods are treated in the cooking and manufacturing process, and with the addition of a range of ingredients not present in the original food: salt, fats, sugars, colors and preservatives, stabilizers and other additives.

Ultra-processed foods are precisely formulated to tease our palates with just the right blend of sweet, salty and fatty flavors. They keep us reaching for more, and at the same time prevent us from feeling completely satisfied.

In terms of food engineering, this is a remarkable feat. But when it comes to health and well-being, there's a potentially steep cost.

Ultra-processed foods are high in sodium, saturated fats and added sugars, which contribute to a range of health problems. These include an increased risk of Type 2 diabetes, cardiovascular disease, lowered immune response, certain cancers, dementia and early death.

As your own experience has shown, a diet high in these types of foods often leads to weight gain and obesity. The findings from a clinical trial, which were published in the journal Cell Metabolism, found that study participants eating a diet high in ultra-processed foods routinely took in 500 more calories per day than those assigned to a diet of whole foods.

Another piece of the puzzle is these types of foods are lacking in the wide range of nutrients needed to keep our bodies functioning well. They are also low in the dietary fibers that keep the beneficial microorganisms of the gut microbiome fed and happy.

You've taken an important step by recognizing the role of highly processed foods in the weight that you have gained. And a diagnosis of prediabetes, which is blood sugar that is higher than normal, is a wake-up call. It means you don't have Type 2 diabetes yet, but without lifestyle changes, you are now at increased risk.

Our inbox shows you're far from alone in your wish to ditch junk food and improve your diet. With that in mind, we will follow up soon with a column that explores strategies for success.

Lichen planus: We recently discussed lichen planus, which affects the skin and sometimes the mucous membranes, including in the mouth. On the skin, it's a shiny, itchy, flat-topped rash, often purplish in color. Within the mouth, it often produces a lacy pattern of white dots that may hurt or burn.

The column prompted this question from a reader: “Can you please advise me as to what specialty of physician would be best able to diagnose the disease?” he asked.

When someone suspects they have lichen planus, a visit to a dermatologist is a good idea. They can recognize the visual symptoms, and if needed for a definitive diagnosis, can remove a bit of skin to be examined under a microscope. In some cases, a blood test may be used to rule out other conditions with similar symptoms.

Beans and diabetes: A column about an intriguing study into the positive effects that black beans can have on insulin resistance caught the attention of a lot of readers. The researchers found that obese mice who ate cooked black beans had improved sensitivity to insulin and an improved gut microbiome. This proved true only when the mice were fed the actual beans, and not components of the beans.

One reader asked for a clarification. “I'm not sure what you mean when you say 'components' from the black beans were not beneficial,” she wrote. “Does that mean pureed or chopped black beans do not have health benefits like whole ones do?”

The benefits come from cooked black beans, no matter how they are treated in preparation or cooking. The “components” in the study refers to certain molecules and nutrients that were isolated from the whole beans. That's not something you can achieve in a home kitchen.

Plantar fasciitis: Many of you have shared your experiences with plantar fasciitis. That's the painful inflammation of the thick band of tissue that connects the heel bone to the toes. A retired pediatrician (and avid tennis player and ballroom dancer) joined several readers in suggesting the use of a splint to brace the affected foot, both at night during sleep and during the day.

“Many of us extend our ankles during sleep and worsen the condition,” she wrote. “Light splints to gently stretch the Achilles tendon at night are fairly comfortable. Heavier splints are good for daytime use, too.”

Night splints keep the ankle in a neutral position, thus passively flexing the calf and gently extending the plantar fascia. While many people find this technique to be helpful, it doesn't work for everyone. For those who wish to try, the devices are affordable and are widely available at drugstores and from online retailers.

• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.