In Part 1 and Part 2 of this series, we established that the body has no requirement for added sugar and explored what it does to the liver, blood, and connective tissue, along with its emerging links to cancer. The good news: Much of that damage responds to change. Start by finding out where you stand.
Signs You May Be Eating Too Much Sugar
No single symptom diagnoses excessive sugar consumption. Frequent hunger after carbohydrate-heavy meals, persistent cravings for sweets, afternoon fatigue, and a nightly need for dessert may be clues. With mood, appetite, and cravings, it’s all about pattern recognition.
Increasing waist circumference, elevated triglycerides, increasing liver fat, rising fasting glucose, and deteriorating glucose tolerance are more concrete signs that metabolic health is worsening. These are red flags that should prompt a closer look at the diet.
Other clues may be visible from the outside. In both children and adults, dental cavities are one of the most obvious signs of a poor diet. Bacteria in dental plaque metabolize dietary sugars and starches and produce acids that demineralize tooth enamel, which is why both the amount and frequency of sugar exposure are strongly associated with tooth decay. Your skin may offer another clue. High-glycemic diets, which produce larger and more rapid increases in blood glucose and insulin, have been associated with acne, and randomized trials have found improvements in acne with lower-glycemic-load diets.
Researchers suspect chronically elevated insulin and insulin-like growth factor 1 (IGF-1) can increase sebum production and influence other acne pathways. Skin tags and patches of dark, thickened, velvety skin around the neck, armpits, or groin, called acanthosis nigricans, can also signal insulin resistance. None of these clues is definitive proof, but when cavities, acne, skin changes, increasing abdominal fat, or worsening metabolic markers appear, it’s time to pull out the magnifying glass and go Sherlock Holmes on your diet.
For many people, the easiest assessment requires no lab testing at all. Look at what you eat and drink in an ordinary week. Write it down. Read the ingredient lists and note anything that contains sugar. You likely won’t be surprised to find sugar in cereal, granola, pastries, candy, and other confections, but you might be surprised to find it in pasta sauce, yogurt, beef jerky, nuts, salad dressings, and other supposedly healthy foods. Get an accurate handle on your total sugar intake.
What Happens When You Stop Eating Added Sugar?
The answer depends largely on how much sugar you were eating to begin with.
Someone who drinks a liter of pop every day has a very different opportunity for improvement than someone whose only added sugar is a small dessert on Saturday night. The larger and more frequent the original exposure, the more significant the change can be when it disappears.
Reducing added sugar decreases the amount of rapidly available glucose and fructose arriving from the diet. Depending on the individual and what replaces those foods, insulin demand may fall, de novo lipogenesis in the liver may decrease, triglycerides may improve, and liver fat may decline. Mood swings driven by wild blood sugar swings (hangry, anyone?) calm down. Replacing sweetened, highly processed foods with protein-rich whole foods makes appetite much easier to manage.
People often want to know how many days it takes to “detox” from sugar, but there is no established sugar-withdrawal timeline in humans. Cravings and taste preferences can change over time, and measurable metabolic changes may take weeks. The pediatric fatty liver trial described in Part 2 produced significant changes in only eight weeks.
The takeaway is not that everyone will feel spectacular by day 10, but that metabolic dysfunction does not have to be a one-way street to doomsville. The body is remarkably adaptive and can respond quickly when the nutritional environment changes.
How Can You Improve Blood Sugar Naturally?
The first strategy is straightforward: Reduce the amount of rapidly absorbed carbohydrate entering the system. Eliminating added sugar and cutting back on refined carbohydrates removes the fastest and most concentrated sources.
The second strategy is to improve the body’s capacity to dispose of glucose. Skeletal muscle is the major destination for glucose after a meal, and both muscle mass and muscle activity contribute to glucose regulation. Resistance training builds a larger reservoir, while muscle contraction itself increases glucose uptake. Walking after meals is a fantastic habit for reducing the glucose burden in the blood.
Food selection can further influence the rate of delivery. Vegetables, nuts, seeds, and whole fruit require more digestive work than sugar, juice, flour, and other refined carbohydrate sources. Eating carbohydrate as part of a mixed meal containing protein, fat, and fiber can also slow gastric emptying and the rate at which glucose hits the bloodstream.
This is also where individual context becomes important. A lean athlete training hard five or six days per week has a much greater demand for glycogen and a very different capacity to handle carbohydrate than a sedentary person with visceral obesity, fatty liver, and an A1C of 6.2%. There is no reason to assume those two people should eat the same amount of carbohydrate.
What Should We Eat?
Start with foods that provide substantial nutrition without delivering large amounts of rapidly absorbed carbohydrate. Meat, fish, eggs, and unsweetened dairy provide protein and essential vitamins and minerals with little glucose load. Non-starchy vegetables provide relatively small amounts of carbohydrate within a bulky, fibrous structure. Nuts and seeds combine modest amounts of carbohydrate with fat, protein, fiber, vitamins, and minerals.
Whole fruit occupies an interesting middle ground. Fruit contains sugar, including fructose, but intact fruit also contains water, fiber, and cellular structure that slow consumption and digestion compared with juice or refined sugar. That physical packaging makes a big difference in how fast and how much we can consume.
Fruit also tends to enjoy an almost sacred nutritional status that deserves some tempered perspective. Yes, it can provide vitamin C, potassium, and a variety of phytochemicals. Still, it is not a particularly dense source of the nutrients humans have the most difficulty obtaining, such as high-quality protein, vitamin B12, highly bioavailable iron and zinc, and essential fatty acids. You don’t need to eat large quantities of fruit just because it is a whole food. Enjoy it, but don’t make it the center of your diet.
CrossFit’s original prescription chose its words carefully: some fruit, little starch, and no sugar. That leaves room to adjust carbohydrate intake to your unique physiology and activity level, but we lead with meat, vegetables, nuts, and seeds for a reason.
What About Artificial Sweeteners?
Once people decide to cut sugar, replacing it with a noncaloric sweetener is an obvious strategy. Diet pop replaces regular pop, stevia goes into the coffee, and sucralose shows up in protein powder. Sugar-free syrups and desserts reproduce sweetness without delivering the same glucose and fructose load.
From a narrow blood-glucose perspective, many noncaloric sweeteners have a clear advantage over sugar because they don’t deliver a large dose of glucose or fructose. If someone replaces two cans of regular pop each day with two cans of diet pop, they remove a significant amount of sugar from their diet.
Whether artificial sweeteners are an ideal long-term solution is a different question. Randomized controlled trials generally find that replacing caloric sugar with low- or no-calorie sweeteners can reduce energy intake and sometimes body weight, particularly when compared with continued sugar consumption. Observational studies have reported associations between high artificial-sweetener consumption and obesity, diabetes, and cardiovascular disease, but those studies are difficult to interpret because people who already have obesity or metabolic disease are more likely to choose diet products in the first place.
Questions also remain about individual sweeteners and their effects on the gut microbiome, glucose tolerance, appetite, and learned preferences for sweetness. The evidence is neither strong enough to declare all noncaloric sweeteners harmful nor reassuring enough to make artificially sweetened foods a health recommendation.
Replacing 50 grams of sugar with a small amount of stevia eliminates a 50-gram sugar exposure. That can be useful, particularly as someone transitions away from a high-sugar diet. But swapping sugar for sweeteners while still expecting every drink, snack, yogurt, and dessert to taste intensely sweet isn’t the right answer either.
For many people, artificial sweeteners can be a useful step away from sugar, but they don’t need to become the destination.
Minimum, Not Maximum
Humans have sophisticated systems for handling glucose and fructose. We can burn glucose immediately, store it as glycogen, convert excess into fat, and manufacture glucose when dietary carbohydrate is scarce. Those systems have allowed humans to survive across an extraordinary range of environments and diets. Unlike most animals, we thrive in nearly every environment on Earth.
What is historically unusual is how much concentrated carbohydrate we can now deliver to those systems, and how quickly we can deliver it. Refining removes physical barriers to consumption and digestion. Industrial food production makes those concentrated sources cheap, abundant, portable, and available every hour of every day, everywhere you go.
So the practical question shouldn’t be, “What’s the maximum amount of sugar I can consume before the wheels come off?” That mindset has us teetering on the brink of a health disaster. Added sugar provides no essential nutrients, so we don’t need to find that threshold in the first place. Instead, ask, “What should I eat to give my body everything it needs to thrive?” Focus on the good stuff and reap the benefits. Save sugary treats for special occasions.
For anyone interested in improving health, the simplest strategy is the one CrossFit has recommended for decades: Eat meat and vegetables, nuts and seeds, some fruit, little starch, and no sugar.
Read Part 1: No Sugar: The Two Words That Matter Most
Read Part 2: The Hidden Costs of Eating Added Sugar
Put It Into Practice
Knowing what sugar does to your body is the first step. Knowing what to eat instead, and how to make it stick, is the next. Join us for Applied Nutrition, a one-day, in-person course where you’ll learn how to build meals around meat and vegetables, nuts and seeds, some fruit, little starch, and no sugar, then leave with a personal nutrition plan you can start the next day. [Find an Applied Nutrition course near you.]
Prefer to learn on your own schedule? Take Nutrition I online and get the fundamentals of CrossFit’s nutrition prescription from anywhere. [Enroll in Nutrition I.]
About the Author
Jocelyn Rylee (CF-L4) and her husband David founded CrossFit BRIO in 2008, starting in a modest 1500 sq ft space and focusing on personal training. Her dedication to excellence has also earned her a position on CrossFit LLC’s Level 1 Seminar Staff, a role that allows her to share her passion and expertise with aspiring coaches. Jocelyn holds specialties in Endurance, Gymnastics, Competition, and Weightlifting and is also a certified Strength and Conditioning Specialist through the NSCA. As a Level 2 Olympic Weightlifting Coach and a Level 3 referee, she has been deeply involved in the sport, even serving as a board member of the Saskatchewan Weightlifting Association for five years. Her achievements include being Saskatchewan’s top-ranked female Olympic Weightlifter from 2012 to 2015, during which she held provincial records in the Snatch, Clean & Jerk, and Total in her weight class. With an MS in Human Nutrition, Jocelyn loves sharing her knowledge on nutrition and performance through her blog and Instagram as “The Keto Athlete,” where she delves into the science of nutrition and its impact on athletic performance.