“The more we have, the more we want – and so continues the vicious cycle.”
We can all agree that sugar is bad for us. No doctor will recommend an increase in daily Snickers bars and Pepsi. And none of us are surprised they wouldn’t.
But why is sugar bad for you? Do you know the physiologic reason?
And what’s with the sugar in fruit? Is it bad too?
When I had a patient ask me why sugar is bad for you, I realized I didn’t really have a good answer. I knew it was high in calories and has little to no nutritional value, and I knew having too much could cause diseases, but I couldn’t tell him exactly why.
So I turned to old college textbooks and resources online I knew I could trust, places like the Cleveland Clinic and ChooseMyPlate.
Not all sugar is created equal
First of all, not all sugar is the same. Depending on it’s make-up, a carbohydrate may be simple or complex. You may have heard that complex carbohydrates are better for you, and this is true; they are whole grains and vegetables that have fiber and more benefits for our bodies. Simple carbohydrates are composed of fewer units and include glucose, fructose, galactose, lactose, sucrose, and maltose. These simple carbohydrates are what can cause health concerns when consumed often and in large quantities.
What Happens When You Eat Sugar
Now I won’t go into the details of how sugars are broken down for energy use (ATP and all that goodness). But when you eat an excess of sugar, that’s when the trouble starts.
Most sugary foods break down into glucose, a single sugar unit. Glucose is used by the body for energy and is also stored in your liver and muscles as glycogen. Your muscles use their stored glycogen as muscle-only fuel. However, your liver releases glycogen for the body as needed, such as for prolonged periods of exercise, fasting, etc.
Some sugary foods are broken down into fructose, which seems to be the worst culprit. Fructose is the simple carbohydrate behind high fructose corn syrup found in sodas, fruit juices, candy, and so much more. When the body has an excess of fructose, the liver stores the extra as fat. Fructose also triggers the liver to produce more cholesterol, which is released into the bloodstream. Sucrose (table sugar) can also have this effect.
Specifically, the liver will then produce more triglycerides, more LDL (bad cholesterol), and less HDL (good cholesterol). Triglycerides and LDL contribute to the clogging of arteries. On the other hand, HDL acts like a broom, “sweeping” away the bad cholesterol back to the liver. When all of these levels are off, you are much more likely to have clogging in your arteries and thus more likely to have a heart attack or stroke. In this case, all from too much sugar.
Effects on insulin
High amounts of glucose can also cause insulin resistance over time. It’s thought that when blood sugar levels (from too much glucose) are consistently high and the pancreas has to release lots of insulin to lower it, your body slowly becomes less and less sensitive to insulin. Therefore, just by continually having large amounts of sugar and thus raising your blood sugar, you can cause yourself to develop type 2 diabetes and have even more blood sugar impairment. Since having high blood sugar in itself can damage the lining of your arteries, it’s extra important to watch your sugar intake. And if you have diabetes it is crucial that you do your absolute best to control your blood sugars every day.
Obesity and other associated problems
It was originally thought that having sugar may be bad simply due to the increased intake of calories. This is certainly part of it, as eating an excess of sugary, high-calorie foods can absolutely lead to becoming overweight or obese. But these bodily processes are all intertwined, as having high amounts of insulin can cause weight gain too.
All of these problems often occur together. Obesity, high blood pressure, high cholesterol, type II diabetes, and heart disease – these regularly coexist. As a cardiac rehab nurse, I can absolutely vouch for this frequently being true. And from what I’ve found, eating a high-sugar is an excellent way to increase the likelihood you’ll become a patient of mine one day. And as great as I’m sure you are, I never want to see you there.
More Sugar, More Cravings
The frustrating thing – and I believe almost every person can agree – is that sugar is sooo addicting. Not only is it impossible to stop eating more candy corn after that delicious first piece (doesn’t matter that it’s like chewing on wax, gimme more!), but it’s also addicting long-term. We get hit by these sugar cravings that are so unrelenting and irresistible. And once you finally satisfy that craving, the pleasurable sensation signals your brain to keep seeking that reward in the future.
Because of sugar’s addictive nature, we of course often eat too much of it. The more we have, the more we want – and so continues the vicious cycle that likely leads to one or more of those problems mentioned above. With sugar being so ridiculously accessible and added sugars thrown into practically everything (#whyissugarinmysaladdressing?) it’s pretty darn hard to avoid. So how much can you actually eat without seeing the negative effects?
Daily Sugar Intake Recommendation
The daily sugar intake guidelines refer to added sugars only. Fruits are NOT included in this! It’s recommended by the 2015-2020 Dietary Guidelines that no more than 10% of your daily calories come from added sugar. Dr. Mark Hyman, a renowned leader in the field of functional medication, shares in an article that the American Heart Association actually recommends no more than 5% – 7.5% of daily calories from sugar. (See his article linked down below).
Added sugar has no nutritional benefit. So while it’s providing your body with calories aplenty, it’s not contributing any vitamins or minerals to nourish you. And once consumed, it’s taking the place of more nutritional foods you could have eaten instead.
For more on added sugars, check out this page by ChooseMyPlate. It shares where added sugars lurk, their common names (time for a nutritional label scavenger hunt!), and how to decrease your intake.
So ultimately, why don’t you want to eat a lot of sugar? Added sugars in excess can damage arteries walls, increase cholesterol, cause insulin resistance, and contribute to weight gain. Ultimately, long-term sugary diets can increase the likelihood of obesity, type II diabetes, heart disease, and strokes. The takeaway? Keep your daily sugar intake within the guidelines above, and strive to change your mindset. High-sugar foods should not be the norm. Eat sugary foods only as special treats in order to keep yourself healthy for longer!
For more on this topic, read Dr. Mark Hyman’s article:
And if all this wasn’t scientific enough for you, this article by the American Heart Association can give you even more detail on your body’s response to an excess of sugar:
Sugar and Cardiovascular Disease: A Statement for Healthcare Professionals From the Committee on Nutrition of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association