There are different types of carbohydrates but for now we’ll focus on the left-hand side in the chart above, labeled Sugars. Sugars, also called simple carbohydrates, tend to taste pretty sweet. A major one of these sugars that you’ve probably heard of is fructose, commonly found in fruit. Although it’s pure sugar, it doesn’t cause a rise in blood sugar levels (another type of sugar (glucose) does raise blood sugar levels, which we discuss below.) Instead it’s commonly sent to the liver, converted to triglycerides and stored as fat. This mechanism is thought by many to be an evolutionary adaptation to have extra fat stores on hand with winter on the way, particularly because there won’t be fruit for months on end. As you follow the fructose chain down in the flowchart, you can see that it can lead to not only insulin resistance but high blood pressure as well.
Glucose is also a big player in the sugar world. This, unlike fructose, causes a rise in blood sugar levels. In fact, the term blood sugar is interchangeably used with blood glucose since glucose is what directly raises blood sugar/glucose. Like fructose, it’s absorbed very quickly, increases hunger and can lead to overeating. It also dramatically raises insulin levels to counteract the rise in blood glucose.
Polysaccharides, also known as complex carbohydrates, are big groups of sugars. These are are called starches, and some of these starches are slow digesting (SDS), some are rapidly digesting (RDS) and some are just plain resistant to any digesting (RS). We’ll dive into these in another post but for now just know they exist. And they can be very beneficial for you for a host of reasons.
The slow digesting starches are great because although they will raise your blood glucose and insulin levels, it’ll be less than what other carbohydrates will do. In terms of your body’s response, rapidly digesting starches create responses similar to simple sugars. Resistance starches are what only your stomach is not able to digest it. Instead, it’s processed by bacteria in your intestines and converted to fatty acids for use in your colon.
So now that you have a primer in simple carbohydrates (sugar), let’s explore the three points at the beginning.
Excess sugar is converted to body fat
A certain amount of glucose is stored as glycogen in our muscles. The glycogen (strings of glucose/sugar molecules) in our muscles gets quickly used for energy when needed for physical activity. So if you start to do a squat, your body will use the glycogen stored in your thighs and butt as energy for that movement. This store of energy isn’t unlimited though--there’s a cap on how much glycogen we can store in our muscles. Once this limit is reached, the excess glucose is converted to body fat.
Also remember that fructose is commonly converted to triglycerides in the liver and then stored as fat. Fructose is found in all fruits, but particularly the very sweet ones. Additionally, fructose does a poor job in making us feel full since it doesn’t trigger the release of insulin or leptin (the hormone that tells us we’ve eaten enough), thus you’re more likely to overeat.
So excess amounts of two main sugars--both glucose and fructose--can increase body fat.
Sugar is linked to insulin resistance and obesity
Your body likes to maintain homeostasis (balance), so when your blood glucose level rises, insulin is released from the pancreas to bring blood glucose back down. But eating excessive amounts of carbohydrates, and especially sugars, will blunt this insulin response. Eventually, your body figures that glucose levels are chronically high and it becomes resistant to insulin. This is called insulin resistance or pre-diabetes. This is commonplace in many Western societies today and many times insulin resistance and obesity go hand-in-hand.
Sugar feeds “bad” gut bacteria
You have over 100 trillion bacteria living in your gut (colon) that compose your microbiome. They can impact everything from food digestion, to your immune system, and risk for metabolic and mental health syndromes. So there is food that feeds that “good” bacteria, but there is also food that feeds the “bad” bacteria. Sugar feeds the “bad” bacteria when it enters your gut because it’s preferentially used by them as fuel. These bad bacteria become stronger and multiply, directly increasing your risk for obesity.
Bringing together these three reasons why sugar is making you fat you can see that:
If you eat too much sugar and don’t deplete your glycogen stores, it’ll convert to body fat
Eating too much sugar can lead to obesity and insulin resistance, thereby causing even more fat gain
Sugar feeds bad gut bacteria, which can immediately lead to fat gain
We’re not saying that carbs and sugars are the enemy, because they’re not. Carbohydrates and sugar have their time and place in a diet focused on longevity and optimal performance. What we’re saying is that the dose makes the poison--and a ton of people are poisoned by excessive sugar.
So we have some compelling arguments showing why sugar is making you fat. But what can you do about it?
Eat a “whole food” diet. Sugar is commonly added to processed foods and is hidden in everything from yogurt to tomato sauce. Eating whole foods, foods with one ingredient, will put you in a much better position to know what you’re eating. Some brands of processed eggs have a half dozen ingredients. A whole egg has one ingredient--the egg itself!
Limit sugar intake to small amounts of nutrient-dense fruits in the evening. By far the most nutrient fruits are the dark, tart berries. Although these berries have sugar in them, they also have a ton antioxidants and micronutrients seldom found elsewhere. Like we said, the dose makes the poison, and it’s excess sugar that’s poisonous. Having a handful of raspberries, cherries, and blueberries will get you vital nutrients. And limiting the amount will ensure the sugar isn’t going to contribute to body fat.
Eat 50% or more of your calories from healthy fat. Our bodies process two things for energy: fats and carbohydrates. Getting the majority of energy from healthy fat ensures that you’ll be satiated because of the leptin release (hormone that tells you you’re full) and will help to prevent overeating. Because you won’t be overeating on a high healthy fat diet, there won’t be any excess dietary fats to convert to body fat either. It’s a win-win situation!
Armed with this knowledge of why sugar is making you fat and the action steps of how to not fall victim to sugar, which action step will you try first? Eating whole foods? Making a few berries at night the majority of all the sugar you eat? Or eating a diet high in healthy fats like grass-fed pastured butter? Let us know in the comments how you’ll stop sugar from making you fat!
In Excellent Health,
Garrett & Luc