The Hidden Danger of “Zero Sugar” Foods & Ultra-Processed Labels | Andrew Koutnik | AFP 51

The following is based on a conversation with Andrew Koutnik, a research scientist in Health, Nutrition & Food Sciences at Florida State University.

How Do “Zero-Sugar” Product Labels Circumvent Sugar Content Declarations?

Food manufacturers leverage legal labeling thresholds and chemical nomenclature to market items as “Zero Sugar”. Under current regulatory frameworks (such as FDA guidelines), if a serving size contains a negligible amount of sugar, companies can round the declared sugar content down to zero. Manufacturers often exploit this by arbitrarily reducing the serving size on the label.

Additionally, companies swap traditional sucrose or high-fructose corn syrup with sugar alcohols like maltitol. Because maltitol has a distinct chemical structure, it is not classified as “sugar” on ingredients lists, allowing for “Zero Sugar” front-of-pack marketing claims. However, maltitol is a carbohydrate with a similar caloric density to sugar that still induces glycemic and insulinemic responses.

What Is the Biological Cascade Triggered by Fasting, and How Does It Compare to a Ketogenic Diet?

Fasting initiates a metabolic shift driven by the suppression of insulin, the primary hormone regulating nutrient storage and release. The physiological cascade follows these steps:

1. Glycogen Depletion & Insulin Suppression: As initial meals are digested and skipped, circulating blood glucose drops, signaling a reduction in insulin secretion.
2. Upregulation of Lipolysis: Low insulin levels act as a metabolic switch, causing the body to reduce glucose reliance and increase fat breakdown (lipolysis) for energy.
3. Ketogenesis: Accelerated hepatic fat oxidation produces ketone bodies, molecules that serve as an alternative fuel source and exhibit anti-inflammatory, antioxidant, and epigenetic signaling effects.

While a prolonged fast achieves this state through total calorie deprivation, a ketogenic diet mimics this metabolic environment by restricting carbohydrates while providing dietary fats and proteins. This allows for sustained fat oxidation and ketone production without forcing the body into severe muscle protein catabolism.

Why Are Refined Carbohydrates Considered the Primary Driver of Metabolic Health Issues in Ultra-Processed Foods?

Refined carbohydrates represent the most prevalent offender within ultra-processed food matrices due to their impact on satiety, caloric density, and metabolic signaling. During processing, the natural fibrous and micronutrient-rich structures of whole foods are stripped away, leaving rapidly digestible starches and sugars.

When consumed—especially alongside added fats or in liquid forms—these refined carbohydrates cause rapid spikes in blood glucose and circulating insulin. Because these engineered food formulations lack fiber and essential micronutrients, they fail to trigger physiological satiety cues (satiation). This hyper-palatability drives chronic overconsumption, leading to energy imbalances, sustained hyperinsulinemia, and an elevated risk for metabolic disorders such as obesity and type 2 diabetes.

Cleaned Transcript

Jeroen Schreel: Welcome to Apple Finch Pudding, your gateway into the world of science. Today’s scientist is Andrew Koutnik, a research scientist at Florida State University. His work focuses on nutrition, metabolism, and lifestyle. Welcome, Andrew.

Andrew Koutnik: An honor to be here, Jeroen Schreel. I know I’m going to call you Jeroen Schreel today because I know it’s the English pronunciation, so I’m going to do my best to stick with it. But yes, I’m ready and excited to be here, man. It’s an honor to talk with you today.

Jeroen Schreel: I think you’re the most excited guest to start with, so thank you for that.

Andrew Koutnik: Hey, I love this! It’s fun. Science is great, and talking about these topics is something I never thought I’d be doing, honestly. I never realized I’d be in a situation where I got to study and talk about things that interested me, explore interesting questions, get answers to things we never knew about in the world, and get paid to do it. So, I feel lucky, I’m excited, and it’s really cool to be here with you.

Jeroen Schreel: Perfect. Before we delve more into your work, do you have a fun science fact for our listeners?

Andrew Koutnik: Oh man, I probably have tons! Listeners probably already know this if they have seen anything about me, but… oh, you got me stumped here, man. Give me a chance. The listeners have to listen to the whole podcast, and at some point along the way, I’m going to throw this out there. But they’re not going to know where it is, so they have to listen to the whole thing.

Jeroen Schreel: That’s a cliffhanger! Really good for engagement, so thanks.

You have studied nutrition and lifestyle for years. Was there a specific moment in your life that triggered your interest in this topic?

Andrew Koutnik: When I was a kid and struggled with obesity, I was curious about how to utilize nutrition as a tool to lose weight first, but also to get bigger, stronger, and faster. Having excess fat tissue at such a young age—where your physical appearance has a high impact on your self-esteem—had a very big impact on me. But back then, it was more of a tool for superficial reasons.

When I was diagnosed with type 1 diabetes at 16 years of age—a chronic, irreversible metabolic disease—everything changed for me. I had to administer insulin every single day at every single meal for the rest of my life. That’s when nutrition, exercise, and lifestyle clearly impacted the most important metrics in my health.

I realized at the same time that the way lifestyle was impacting my health was something research was just beginning to understand. What I was learning in real-time was hidden from much of the rest of the world because they didn’t have it uncovered due to a disease diagnosis like I did. I felt lucky; I felt I had an asset and an opportunity. That’s what led me to become passionate about science and get involved in research.

I didn’t know I’d be sitting here talking to you as a research scientist. I just knew I woke up and spent 80% of my time thinking about nutrition, exercise, getting bigger, stronger, faster, glucose levels, and insulin levels. I just happened to find a way to get paid to do it, which is crazy to me. That’s really where my journey in science began.

Jeroen Schreel: You mentioned you have diabetes. Is that actually caused by bad nutrition?

Andrew Koutnik: What’s interesting about this is that nutrition certainly plays a role in type 2 diabetes. In fact, we’ve known for over two centuries that changing nutrition can prevent, manage, and reverse type 2 diabetes.

Type 1 diabetes is a little bit different. It’s an autoimmune disease that causes the body to destroy parts of the pancreas that produce insulin. Because you no longer produce insulin, you are largely reliant on manually manipulating insulin administration to replicate what your metabolism used to do automatically.

A lot of people used to believe that lifestyle factors didn’t impact type 1 diabetes or lead to an elevated risk for diagnosis. But what we’ve come to realize is that lifestyle factors like obesity increase the risk for many autoimmune diseases, including type 1 diabetes. Recent analyses in journals like PNAS suggest nutrition explains over 90% of the obesity epidemic. Between nutrition and exercise, nutrition outweighs exercise nine-to-one comparatively in driving obesity.

While we once thought poor lifestyle habits weren’t a cause for an autoimmune diagnosis, we now realize that lifestyle factors modulate those underlying risks. If you had asked me two years ago, I would have given you a different answer. I used to respond that lifestyle didn’t have much of an impact. But looking at emergent evidence on what puts people at risk, obesity is a primary leading risk factor for developing these diseases, and obesity is a lifestyle factor.

Jeroen Schreel: It’s good for people to be reminded that science and insights change over time. I’m happy I’m getting your most recent answer.

I want to read this back to make sure I paraphrase you correctly: You stated, “Good nutrition tailored to your specific needs, exercising as much as you can, and getting good sleep are the pillars of health.” This invokes some questions, like: what is good nutrition?

Andrew Koutnik: That’s a great question. What someone does for their nutrition is an individualized journey, but there are fundamentals to good nutrition.

Number one is focusing on whole foods—typically unprocessed foods. These foods tend to have fewer additive ingredients or refined components that make it difficult to eat in moderation or cause adverse responses. Additives are often there for flavoring, stabilization, texture, or sensory experience rather than nutritional value, ultimately reducing the quality of the food. Focusing on unprocessed whole foods is a powerful first step.

The second approach—which goes hand-in-hand with whole foods—is eliminating liquid calories. This is one of the quickest ways to remove the least nutrient-dense calories people consume. Sodas, sugar waters, and even fruit drinks are largely just repackaged sugar water. Removing them eliminates calories that are void of micronutrients and fiber. Typically, liquid calories don’t provide satiation, leading people to consume excess calories, which creates metabolic issues like obesity.

From there, you can consider the specific type of food pattern. For individuals with obesity, type 2 diabetes, or type 1 diabetes, specific patterns—like protein-focused, higher-fat, low-carbohydrate diets—can be effective. This doesn’t mean zero carbohydrates; foods like salads, cauliflower, and spinach are included while eliminating breads and starchy carbohydrates. That is an effective therapeutic strategy to control glucose and insulin levels.

Beyond dietary patterns, you consider food quality within that pattern: Are you consuming nutrient-dense foods? What type of fat is it—saturated or polyunsaturated? What type of carbohydrates are you consuming, and do they have high fiber or phytonutrient content?

To summarize the hierarchy:

1. Focus on whole, unprocessed foods.

2. Remove liquid calories (focus on water or sparkling water).

3. Choose a dietary composition that fits your specific needs.

4. Optimize food quality within that diet.

Regarding exercise: any type of movement is better than no movement. Sitting is worse than moving, and moving more is better than moving less. Incorporating structured endurance and resistance training maximizes your return on investment. Exercise operates on a dose-response curve: hitting higher thresholds of volume (duration and intensity for endurance; sets, reps, and weight for resistance) yields greater benefits.

When it comes to sleep: sleep is critical for overall health. When someone gets poor sleep, their cognition is impaired, impulse control drops, nutritional decisions worsen, and metabolic health declines. Good sleep improves cognition, impulse control, physical performance, and overall quality of life.

All of these strategies can be implemented without spending a single penny. Nutrition is simply a decision of where you reallocate your grocery budget. For exercise, you can walk, run, or do bodyweight exercises outside for free. For sleep, getting sunlight exposure first thing in the morning and eliminating screens and bright lights at night helps you settle down faster and improves sleep quality.

These basic strategies aren’t as “sexy” as taking a magic pill, but singular quick fixes never work long-term. Sacrificing an hour to exercise or passing up highly palatable, low-nutrient food gives you back 24 hours of feeling good, rather than 10 minutes of pleasure that ruins hours of your day.

Jeroen Schreel: You covered a lot! We have the essentials down now. I get what you’re saying about avoiding candy—once you start, it’s difficult to stop because it feels addictive. That ties into ultra-processed foods. Could you define what ultra-processed foods are so people can identify them at the store?

Andrew Koutnik: Scientists are actually struggling today with how to define processed food because even healthy foods, like plain yogurt, require some degree of processing.

In simple terms: think about packaged foods that are significantly transformed from their whole-food origins. Take a cracker, for example. You don’t see crackers in nature. A food source has been heavily processed down into a completely different texture, loaded with components to turn flour into a dry, crispy snack that is hard to consume in moderation.

When evaluating food:

1. Is it packaged?

2. Has the food been significantly transformed to increase flavor at the expense of quality?

3. Are sugar or flavoring agents listed within the first three ingredients?

Ingredients are listed by weight. If sugar or its equivalent appears in the first three ingredients, that food was likely engineered to make it hyper-palatable and calorically dense, making it difficult to stop eating.

For example, if you make a bowl of beef and rice at home, you use two to four ingredients: beef, rice, salt, and maybe oil. If you look at a frozen beef and rice meal at the grocery store, it might contain 20 to 40 ingredients, with sugar near the top. Why add sugar to beef and rice? Because it makes people want to consume more.

The worst offenders in processed foods are refined carbohydrates, which carry the strongest evidence for driving obesity.

Jeroen Schreel: A lot of people assume crackers are healthy because they are dry and made of wheat or flour. Is it the carbs or something else that makes them suboptimal?

Andrew Koutnik: I wouldn’t say crackers are inherently “unhealthy”—health quality depends on context. No single food is inherently toxic on its own, just as no single “superfood” will fix everything.

The problem with crackers is that people rarely eat them plain; they usually dip them into calorie-dense spreads.

Even sugar or fruit isn’t inherently bad, but context matters. For instance, a person with type 1 diabetes can use fruit juice to rapidly raise critically low blood sugar. However, consuming large amounts of high-glycemic fruits regularly on a daily basis will cause rapid glucose and insulin spikes. Context determines whether a food is optimal or suboptimal for an individual.

Jeroen Schreel: Do you define ultra-processed items as “food-like substances,” or do you just consider everything in the store as food?

Andrew Koutnik: I don’t break it down to “food-like substances” because that isn’t functional for the average shopper. People at the store simply ask: Does this taste good? Is this healthy for me?

Navigating the grocery store can feel like a landmine. You almost need an advanced degree in nutrition to understand the marketing tricks companies use on labels. I actually have an example right here on my floor: a major brand put “Zero Sugar” prominently on the front of their product.

Jeroen Schreel: Which implies it won’t cause excess sugar consumption.

Andrew Koutnik: Exactly. But when you look at the ingredients on the back, they swapped sugar for maltitol. Maltitol is a carbohydrate with a chemical structure distinct from sugar, allowing them to claim “Zero Sugar” on the front. Gram-for-gram, maltitol delivers a similar caloric load and still elevates blood glucose and insulin. Nothing changed metabolically; they just swapped sugar for a sugar alcohol because consumers wised up to the word “sugar”.

That is why focusing on whole, unpackaged foods gives you total control. You don’t have to put your trust in corporate marketing.

Jeroen Schreel: What product is that on your floor?

Andrew Koutnik: It’s a package of Reese’s Cups. On the front, the words “ZERO SUGAR” are printed four to five times larger than the actual brand name. The back says, “Your favorites without the sugar.”

Yet, looking at the nutrition panel, it has a high total carbohydrate count. The number one ingredient listed is maltitol. It acts like sugar, raises blood glucose, raises insulin, and has similar calories. It’s a marketing trick to proclaim health benefits on a product that offers no real metabolic improvement over the original version.

Jeroen Schreel: That happens a lot. For example, do you know how much sugar is in a “sugar-free” Tic Tac?

Andrew Koutnik: I’m guessing either it has sugar equivalents, or they shrank the serving size down to a single Tic Tac so the sugar content falls below the threshold required to declare it on the label.

Jeroen Schreel: Exactly! Tic Tacs are almost entirely sugar, but because one serving is a single Tic Tac, the sugar amount per serving is low enough that regulations allow them to label it as zero sugar.

Andrew Koutnik: That is a classic trick. FDA rules have specific thresholds, but there is ambiguity and allowed estimation error. Food companies exist to make money, and their incentives don’t always align with your health. You have to be your own advocate.

That said, not all packaged items are bad. I consume protein powders and bars because they are convenient for my busy schedule with two kids. But I carefully select products high in protein, lower in total calories, and minimal in glycemic impact. Many popular “health” bars are essentially candy bars in disguise.

Jeroen Schreel: What are three foods people think are healthy that you would avoid, and conversely, what are foods people avoid that are actually healthy?

Andrew Koutnik: Oatmeal is one. While raw oats aren’t inherently bad, many commercial, highly processed instant oatmeals spike blood glucose rapidly.

Another is orange juice and fruit drinks. People assume they are healthy, but many bottled juices list added sugar as a main ingredient. When you turn fruit into juice, you strip away the structural fiber and micronutrients, leaving behind what is essentially sugar water.

On the flip side, foods like eggs and beef have been unfairly vilified. Researcher Ty Beal published analyses examining nutrient density, showing that beef ranks among the most high-quality, nutrient-dense foods available.

Consuming massive quantities of saturated fat alongside massive amounts of refined carbohydrates can cause metabolic issues. But within a balanced, low-carbohydrate context, whole food sources of saturated fat like eggs and beef fit well and support overall health. Health can be summarized in one word: balance. Disease and metabolic dysfunction arise in the absence of balance.

Jeroen Schreel: So it’s about consistency over time.

Andrew Koutnik: Consistency is critical. A theoretically “perfect” plan is useless if you can’t sustain it. Consistently executing a 50% ideal plan will yield far better long-term results than failing at a 100% ideal plan.

Jeroen Schreel: Some people think they can eat poorly and fix everything by fasting occasionally. What is happening in the body during a fast?

Andrew Koutnik: Fasting has historical roots in religious traditions, but biologically, abstaining from food triggers a distinct metabolic cascade:

1. Glucose drops: Skipping meals causes blood glucose levels to decrease.

2. Insulin drops: Lower glucose signals a drop in insulin, the primary hormone regulating energy storage.

3. Fat oxidation increases: With insulin low, the body switches from relying on carbohydrates to burning fat for fuel.

4. Ketone production: As fat breaks down, the liver produces ketones, which exert anti-inflammatory, antioxidant, and gene-signaling benefits.

Data shows that during a multi-day fast, virtually every tissue in the body undergoes adaptations, largely driven by nutrient absence and low insulin.

However, extended fasting has downsides. Early in a fast, the body breaks down muscle tissue alongside fat to supply energy. Frequent prolonged fasts can compromise lean muscle mass. Extended fasting for three days occasionally (e.g., quarterly or annually) can provide a reset, but it isn’t necessary for everyone. Exercise provides similar metabolic shifts by depleting glucose and lowering insulin without requiring prolonged starvation.

Jeroen Schreel: Do you fast regularly?

Andrew Koutnik: I don’t fast often—maybe once a year for three days if I feel like resetting. Because I participate in high levels of athletic training, prolonged fasting interferes with my performance and recovery.

Jeroen Schreel: You mentioned ketones. Can you explain the ketogenic diet and its therapeutic applications?

Andrew Koutnik: The ketogenic diet has been used medically for over a century, originally to treat epilepsy and manage diabetes before synthetic insulin was developed. Systematic reviews show it helps reduce pain and systemic inflammation.

A ketogenic diet is a very low-carbohydrate, higher-fat approach that forces the body to shift primary fuel reliance from glucose to fat and ketones. It mimics the underlying metabolic state of fasting without caloric deprivation.

Emerging clinical trials are investigating ketogenic therapies for psychiatric and mental health conditions, including anxiety, schizophrenia, and bipolar disorder.

People often view keto as extreme, but that perception is skewed by modern grocery stores where 70% of packaged products consist of refined carbohydrates. If a store contained only whole foods—meats, fish, dairy, leafy vegetables, and berries—over half of those foods would naturally be keto-compatible.

Jeroen Schreel: If someone wants to try a ketogenic diet, how should they substitute high-carb staples like rice?

Andrew Koutnik: A great strategy is replacing high-carb items with low-carb alternatives, like swapping white rice for cauliflower rice. You can also find or make low-carbohydrate breads and options using alternative flours.

An easy way to start:

1. List the foods you eat in a typical week.

2. Use an AI tool (like ChatGPT or Gemini) to identify which items are low-carb/ketogenic and which are not.

3. Ask the tool for low-carbohydrate swaps for the non-compliant items that match their texture and taste.

This allows you to preserve your daily eating routine while lowering your carbohydrate footprint.

Jeroen Schreel: What if someone doesn’t want to eliminate carbs entirely, but just reduces them? Does that help?

Andrew Koutnik: Yes! Studies show that restricting carbohydrates to under 130 grams per day improves insulin sensitivity and helps reverse pre-diabetes. While greater carbohydrate restriction yields more pronounced therapeutic effects, any reduction is better than none. Progress over perfection.

Jeroen Schreel: What concerns you most right now regarding general public health?

Andrew Koutnik: You have to be your own health advocate. Modern food environments and healthcare structures are not set up to optimize your daily health. No doctor is going to come to your home to ensure you exercise, sleep eight hours, or eat whole foods.

Take ownership of your lifestyle habits. If you don’t know where to start, consider working with a qualified coach or learning from individuals who have successfully achieved the health outcomes you want.

Jeroen Schreel: Do you have a final take-home message for our listeners?

Andrew Koutnik: Health is a marathon, not a sprint. Don’t expect to transform your body, diet, and metabolic health overnight. Focus on taking the first actionable step today. Consistent small steps add up to finishing the marathon.

Second, trust your own results. If a clinical study suggests a specific diet is optimal, but you implement it properly and feel terrible, trust your body. Scientific papers report population averages, but you are an individual. Find what works for your unique physiology, take the first step, and stick with it.

Andrew Koutnik: Health is a marathon, not a sprint. Don’t expect to transform your body, diet, and metab properly and feel terrible, trust your body. Scientific papers report population averages, but you are an individual. Find what works for your unique physiology, take the first step, and stick with it.

Jeroen Schreel: That’s a great reminder, we are individuals, not statistical averages. This was Apple Finch Pudding. I want to thank Andrew Koutnik for sharing his expertise. Join us again for the next episode of Apple Finch Pudding!

Relevant Papers

• Noakes et al., 2026. Carbohydrate Ingestion on Exercise Metabolism and Physical Performance. Endocrin Reviews, 47: pp. 191-243; https://doi.org/10.1210/endrev/bnaf038
• Prins et al., 2023. Low and high carbohydrate isocaloric diets on performance, fat oxidation, glucose and cardiometabolic health in middle age males. Frontiers in Nutrition, 10: Article 1084021; https://doi.org/10.3389/fnut.2023.1084021
• Prins et al., 2025. Carbohydrate ingestion eliminates hypoglycemia and improves endurance exercise performance in triathletes adapted to very low- and high-carbohydrate isocaloric diets. American Journal of Physiology – Cell Physiology, 328: pp. 710-727; https://doi.org/10.1152/ajpcell.00583.2024
• Noakes et al., 2023. Low carbohydrate high fat ketogenic diets on the exercise crossover point and glucose homeostasis. Frontiers in Physiology, 14: Article 1150265; https://doi.org/10.3389/fphys.2023.1150265
• Lennerz et al., 2021. Carbohydrate restriction for diabetes: rediscovering centuries-old wisdom. The Journal of Clinical Investigation, 131: Article e142246; https://doi.org/10.1172/JCI142246
• Watso et al., 2024. Advanced cardiovascular physiology in an individual with type 1 diabetes after 10-year ketogenic diet. American Journal of Physiology – Cell Physiology, 327: pp. 446-461; https://doi.org/10.1152/ajpcell.00694.2023
• Araújo et al., 2019. Prevalence of Optimal Metabolic Health in American Adults: National Health and Nutrition Examination Survey 2009-2016. Metabolic Syndrome and Related Disorders, 17: pp. 46-52; https://doi.org/10.1089/met.2018.0105
• O’Hearn et al., 2022. Trends and Disparities in Cardiometabolic Health Among U.S. Adults, 1999-2018. Journal of the American College of Cardiology, 12: pp. 138-151; https://doi.org/10.1016/j.jacc.2022.04.046