Here’s Why You Shouldn’t Eat Sugar

It often surprises me how many people don’t know what is and isn’t healthy when it comes to food. I suppose I shouldn’t be so shocked – after all, contradictory studies come out almost weekly claiming that eggs/bread/fruit/meat/cheese are good/bad for you. One week you’re told to make smoothies, and the next you’re told they’re too sugary. One week you’re told to eat avocados, and the next you realize how high they are in fat.


I mentioned last week that my friend Alyssa is trying out the Whole30 in an effort to eat better. Last Sunday before meal prepping, we went to the grocery store to buy lots of healthy, sugar-free foods. Alyssa was stunned to learn that “healthy” things like tomato sauce, yogurt, granola bars and almond milk all contained added sugar. So many low-fat, vegetarian-friendly foods are actually really pretty bad for us – and many people have no idea.


Silk coconut milk: 7 g of sugar per cup (cane sugar no. 2 ingredient)

Sugar is not a healthy ingredient. Period. I mean, having a Christmas cookie or two in December with your family members is good for the soul, but eating sugary foods on a regular basis (in cereals, yogurts, milks, cheeses, sauces, dips, packaged meals, canned soups, etc.) is horrible for your health. I’m pretty selective about my food choices, even when I’m not trying a new diet or trying to lose weight, so I am pretty knowledgeable about avoiding processed, sugar-laden foods – but so many of my friends and family are not.

PicMonkey Collage yogurt

Greek Gods greek yogurt – Honey Vanilla: 33 g of sugar per cup (cane sugar no. 2 ingredient)

Now, obviously I’m not a doctor. I’m not even a nutritionist, and I’m not trying to give you any kind of dietary advice. But as a health and nutrition writer (and a lover of food), I have learned a thing or two about staying healthy. Here’s a little bit of background information on why sugar is so bad for you and what foods you should steer clear of.


Special K protein bars – Chocolate Peanut Butter: 15 g of sugar per bar (sugar no. 2 ingredient)

Why is sugar bad for you?

In order to understand why sugar is bad for your health, it helps to understand what it is and how the body uses it. There are two basic sugar molecules that we need to concern ourselves with: glucose and fructose. Fructose is the really sweet stuff – it’s found naturally in fruits, and we often see it most highly concentrated in good, old-fashioned table sugar.


Bear Naked granola – Sea Salt Caramel Apple: 28 g of sugar per cup

Glucose – the sugar molecule found in starches and breads – is more complex than fructose. It’s also a pretty great source of energy for the body, as it’s readily available in pretty much any carbohydrate. However, glucose itself isn’t a readily available source of energy; it has to be synthesized through a process called glycolysis. This process takes place within the body’s cells, which means that glucose has to be shuttled into the cells – and that, my friends, requires insulin.

You’ve probably heard about the growing Type 2 diabetes epidemic. We’ve seen a 33% increase in diabetes diagnoses over the past ten years. Among other reasons, people become insulin-resistant when their bodies are exposed to high amounts of glucose for a sustained period of time. The body releases insulin to bring glucose into the cells, keeping blood sugar levels stable in the process. But when blood sugar levels are consistently high, it requires more and more insulin to get the job done, leading to Type 2 diabetes.


Barney Butter almond butter: 3 g sugar per 2 tablespoons (sugar no. 2 ingredient)

Even apart from T2 diabetes, sugar has negative effects on health. Our cells can use either fats or glucose for energy. When our bodies use glucose as our primary source of energy, is allows us to retain fat. This makes sense when you think about it: Fat warms our bodies and prepares them for periods of famine. Our bodies want to store fat. When we consume carbohydrates, we derive our energy from glucose. But in the absence of glucose, our bodies are fully capable of deriving energy from fats. This is why low-carbohydrate diets are so effective: Peoples’ bodies turn to their fat stores for energy, rather than available glucose.

Even if you don’t have excessive body fat, eating a diet rich in healthy fats and low in carbohydrates gets your body into a fat-burning state, creating a cycle that’s independent of spikes and falls in blood sugar. In short: You feel a lot better and have a lot more energy!

So what about fructose? Fructose doesn’t act the way glucose does in the body in terms of providing energy to the cells or requiring insulin. But unfortunately, it does seem to linked with obesity, metabolic diseases, elevated triglycerides, inflammation and other problems. Scientists attribute these negative effects to the high number of calories in sugary foods.

Other benefits to avoiding sugar, in both forms: You do less damage to your cells. You reduce your risk for Type 2 diabetes, Alzheimer’s disease, obesity, and all of the chronic conditions that have been linked with chronic inflammation (cancer, arthritis, depression and anxiety, skin conditions such as acne, and even heart disease).

What kinds of foods contain sugar?

As I mentioned above, there are two kids of sugar we need to worry about: glucose and fructose. Glucose is most often found in things you probably assume to be healthy – things like oatmeal, whole grain bread, granola, rice, pasta and corn. It’s also found in many different fruits and vegetables, just at lower concentrations. Fructose is found in anything containing sugar (or any of its variants, including high-fructose corn syrup, brown rice syrup, etc.), as well as fruits, honey, maple syrup, agave and the like.

My advice would be to stick to fresh vegetables, fresh fruits, nuts, seeds, meat, seafood, beans and legumes. If you need to buy pre-packaged foods, READ THE LABELS and avoid anything that lists sugar, corn syrup, brown rice syrup, et. al. as its first, second or third ingredient.

What about fruit? And whole grains?


So, we talked about the effects of glucose on the body, and we know that that fructose is calorie-dense, and therefore has similar ill health effects. But what about fruits, which are chock full of fructose? Well, two things: First of all, fruits contain a lot of fiber, which regulates digestion and helps prevent inflammation. Second of all, even fruit shouldn’t be consumed in excess. Sugar is sugar (as that stupid high-fructose corn syrup commercial reminds us). Our ancestors only got to enjoy fructose in the high concentrations found in fruit during the peak of summer – we get to enjoy them every day. To account for the difference, we should practice moderation in our fruit consumption. I like to have one or two fruits per day, and try to eat low-sugar fruits (like berries and grapes) when I can.


Now onto whole grains. Here’s the thing: While whole grains absolutely contain glucose and require insulin to harness for energy, they are more complex than simpler carbs (like white bread) and take longer for the body to digest and synthesize. As a result, they have a more moderate impact on blood sugar levels: Insulin production tends to remain steady in relation to these more gradual rises and falls in sugar levels. So whole grains are better than refined grains, but you should still avoid eating them in excess. I like to stick to one serving of whole grains per day.



Holy cats, that was a lot of info! I hope I didn’t get too nerdy on you. It’s weird how much I love writing about nutrition (and talking about it, as my close friends will grumpily verify). The thing is, I love my body. I respect it. I love taking care of it.

I remember the year my relationship to nutrition changed: my senior year of high school, when I took AP Biology. Learning how my body worked made it that much more important to me to take care of it. Understanding those processes and mechanisms – and seeing how incredibly cool and meticulous they are – made me want to help my body function at its absolute best. And ten years later, I’ve never looked back. I indulge from time to time, sure, but I know my body is well equipped to handle whatever I throw at it. It’s happy with me, and the feeling is mutual.

  1. I agree with you completely. An occasional cookie or two is good for the soul, but it’s insane how many people depend on processed high-sugar foods every single day. I think it’s out of confusion more than anything.

    1. I know, right? It’s unfortunate how little knowledge there is out there about food ingredients and labels.

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