Jeremiah Farias

Carbohydrates: Will Eating Carbs Lead to Diabetes?

Written by Jeremiah Farias on July 3, 2020

In some health circles, the spotlight has gravitated away from dietary fats as the culprit for one’s health problems and is now on carbohydrates. With the growing popularity of low-carbohydrate and ketogenic diets, we may hear from the media and health professionals that eating carbohydrate-containing foods, of any kind, will lead to fat gain and is impeding on you reaching your health goals.

Is it true that eating carbohydrates will lead to fat gain? No, not necessarily. Will eating carbohydrates impede you from reaching your health goals? Again, not necessarily.

There may be individuals with certain metabolic conditions or who are prone to overeat, that could benefit from limiting certain forms of carbohydrates. But we should not blanketly demonize all carbohydrate-containing foods.

This article will cover:

  • What Are Carbohydrates?
  • Is It Possible to Eat Carbohydrates and Still Lose Fat?
  • What Types of Carbohydrates Should We Be Eating?
 

We will begin by looking at some background information into what carbohydrates are, just as I have done when discussing previous macronutrients (protein & fat).

What Are Carbohydrates?

Carbohydrates are spilt into two categories:

  • Simple Carbohydrates
    • Monosaccharides 
    • Disaccharides
  • Complex Carbohydrates
    • Oligosaccharides
    • Polysaccharides

Monosaccharides, as its name implies, includes a single unit of sugar. Examples of monosaccharides are Glucose, Galactose, and Fructose. Monosaccharides will not be broken down further via digestion but can be further utilized by the body through a powerful chemical oxidizing agent or glycolysis (which degrades glucose, galactose, and fructose into pyruvate). Pyruvate is then used in the Krebs Cycle (aka the Citric Acid Cycle or Tricarboxylic Acid Cycle) for the production of ATP, our energy currency. Pyruvate, in the absence of oxygen (anaerobic environment), can be reduced to lactate or converted to the amino acid alanine. (Gropper & Smith, 2013, pg. 64)

Disaccharides are composed of two monosaccharides. They are Lactose, Sucrose, Maltose, and Trehalose (not often discussed). You can refer to the diagram to understand which of the monosaccharides make up each disaccharide. Disaccharides are broken down via digestive enzymes into monosaccharides to be used, as energy. For example, lactose is broken down via the enzyme lactase (-ase indicates an enzyme) into glucose and galactose. So those who are lactose intolerant do not possess the enzyme lactase at sufficient enough levels to digest products containing the disaccharide lactose. (Gropper & Smith, 2013, pg. 67-68)

Oligosaccharides consist of 3-10 units of sugar and are present in foods such as beans, peas, bran, and whole grains. Our body does not possess the enzymes required to digest oligosaccharides, so instead of using them for energy, the bacteria in our digestive tract break them down, which can result in gas production (flatulence). (Gropper & Smith, 2013, pg. 68)

Polysaccharides have 10 or more units of sugar and include starch, glycogen, and cellulose. Starch is the primary source of energy we obtain from eating plant foods, and glycogen is the storage form of glucose found in our muscle tissue and liver. Though glycogen is stored in muscles, and we eat the muscle tissue of animals, we get little carbohydrates when eating meat. Cellulose, similarly to oligosaccharides, cannot be digested by humans; therefore, it is not an energy source for us, but the colonic bacteria. (Gropper & Smith, 2013, pg. 68-69)

Figure from Advanced Human Nutrition and Metabolism, 6th Edition.

All carbohydrates, except those we are incapable of digesting, end up as glucose to be utilized by our body for various purposes. With this in mind, we will go to the next portion of the article.

Is It Possible Eat Carbohydrates and Still Lose Fat?

You have heard this before, but I will reiterate; to lose body fat, one needs to be in a caloric deficit. So the amount of calories you consume each day needs to be less than the calories you burn. That is all that matters! As I stated in my article on Fat, there is an array of macronutrient breakdowns one can adopt. What I believe is important is ensuring adequate protein. Regardless of your goal, fat loss or gaining muscle, eating adequate protein will ensure the maintenance of muscle mass while in a caloric deficit so, the weight you do lose is more likely to be body fat and not muscle.

While total calories are what truly matter, I want to cover two additional components one should consider when deciding to include carbohydrates in your diet. They are:

  • Palatability
  • Post-Prandial Glucose Response

Palatability

Palatability is the pleasure or reward we receive from consuming foods or beverages. Food provides satisfaction. Whether you prefer salty/savory or sweet, certain foods seem near impossible to stop eating.

Why am I bringing this up?

If your goal is weight loss, then yes, you need to eat at a caloric deficit. But, is it wise to include foods that are highly palatable when aiming for weight loss? Maybe not. Sure, you can lose weight eating Twinkies, donuts, and chips; but you will have a much harder time staying below calories, being satisfied, and you may be sacrificing your health in other ways. An inpatient randomized controlled trial by Hall et al., found those who ate a diet of ultra-processed food ate more calories which lead to greater weight gain. You may not only be consuming a lot of highly processed vegetable oils but are also putting yourself at risk for nutrient deficiencies, as highly-processed foods are devoid of nutrients (vitamins and minerals).

What makes food highly-palatable?

Combing fats, carbohydrates, sugar and/or salt.

When you combine fats and carbohydrates, you are making food much tastier, and the more tasty something is, the easier it is to overeat. A loaded baked potato with sour cream, butter, cheese, and bacon has a lot going on. You have the starch from the potato along with fat and salt from the other items, making it nearly impossible to not eat the entire potato!

Does this make a loaded baked potato bad? No. Just consider what your goals are and realize it may not be wise to consume hyper-palatable food if your goals are fat-loss. Interestingly, plain potatoes are very satiating (filling). If you boil or even bake a potato and attempt to eat it plain, you will most likely find you can only eat so much.

Combing fats, carbohydrates, sugar and/or salt.

When you combine fats and carbohydrates, you are making food much tastier, and the more tasty something is, the easier it is to overeat. A loaded baked potato with sour cream, butter, cheese, and bacon has a lot going on. You have the starch from the potato along with fat and salt from the other items, making it nearly impossible to not eat the entire potato!

Does this make a loaded baked potato bad? No. Just consider what your goals are and realize it may not be wise to consume hyper-palatable food if your goals are fat-loss. Interestingly, plain potatoes are very satiating (filling). If you boil or even bake a potato and attempt to eat it plain, you will most likely find you can only eat so much.

Baked Potato - Source: Canva

With that said, I do believe that food should taste good. What is the point of losing fat/improving your health if you can no longer enjoy food? I bring this up only to put it on your radar. You can, and should, salt your food to taste and use a variety of herbs and spices to make food delicious. But if you have been struggling to lose fat because you tend to overeat, reducing the flavor options and not combining carbohydrates, fats, and salt may allow for better adherence, in the short-term.

Next, we will discuss the post-prandial glucose response.

Post-Prandial Glucose Response

The post-prandial glucose response is the amount your blood sugar rises after eating a meal. While it may not be something you have thought about, it is an important marker of health. Elevated levels of sugar in our blood cause damage to our arteries, and if our blood glucose remains chronically elevated this can be an indication of insulin resistance. Chronic insulin resistance is a condition that can lead to Type 2 Diabetes if unaddressed. 

Diving into how insulin resistance occurs requires a whole other article, so at the moment, we will focus on how carbohydrates and post-prandial blood glucose levels are connected, and why it matters. 

Of all the macronutrients, carbohydrates elicit the largest spike in insulin. This is due to insulin’s role in storing energy, in this case, storing glucose. The more blood glucose, typically, the more insulin required, but depending on one’s metabolic health and physical activity, glucose can enter the muscles without insulin. Another reason why improving your body composition by ensuring adequate muscle mass is beneficial. As you can see from the chart below; protein and fat will also spike insulin in response to increased blood glucose levels but to a lesser, yet more prolonged degree.

Just because carbohydrates result in the most pronounced rise in blood glucose, this does not mean you should not consume them. What is important is your body being able to clear that glucose from your bloodstream, levels not going above 140 mg/dL, and your glucose levels normalize after about 2-hours. Interestingly, everyone is unique in how they respond to carbohydrates. There was a study done out of Israel, where subjects received various carbohydrate-containing foods and experienced differing responses. For example, one subject would eat a cookie on one occasion and then a banana on another. Both contained the same amount of carbohydrates; in this case, it was 20 grams. While most would imagine the cookie would result in a greater spike in blood glucose than a banana, this is not what the researchers found. Some subjects experienced a greater spike in glucose from eating a banana, where a cookie did not impact glucose levels very much. The opposite was also observed. Some responded to the cookie but not to the banana. 

What is the point in bringing this up? What works for one person may not be the best option for you. To be metabolically healthy and reduce your risk of insulin resistance, understanding that keeping blood glucose levels under control is extremely important.

How can you do that?

So, Can We Lose Fat and Eat Carbs?

Absolutely!

When striving to lose weight food choice is important. Limiting your access and intake to hyper-palatable food will most likely serve you well in your fat loss and health endeavors. Additionally, eating whole food carbohydrates in the context of a complete meal alongside adequate-protein, vegetables, and possibly some healthy fat reduces blood glucose excursions, which allows for better energy and improved metabolic health. There may be certain carbohydrates that raise your blood glucose levels to a very high degree. So, if you notice, despite eating a healthy diet and maintaining healthy body composition, that your blood markers are out of a healthy range, working with your practitioner and/or a registered dietitian to get to the root cause of your altered lab markers may be beneficial.

What Types of Carbohydrates Should We Be Eating?

We know what carbohydrates are and that carbohydrates can be a part of one’s fat loss nutrition plan. In the last section, we will go over what types of carbohydrates we should be eating. 

As with most answers I provide, the types of carbohydrates one should eat depends on the individual’s goals. There are many sources of carbohydrates; such as fruits, vegetables, potatoes, whole grains, white rice, and beans, to crackers, chips, rice cakes, and donuts. 

When making decisions on what to eat, I do believe opting for whole, minimally processed food, the majority of the time is wise.

As I previously mentioned, the more processed a food, typically, the better it tastes. The more palatable a food the easier it is to overeat, and the harder it is to maintain a caloric deficit. But is there a situation where one would want to eat slightly more processed carbohydrates?

Yes! I can think of two. 

First, think about an individual with goals of building muscle mass. This person will need to be in a caloric surplus, so eating more calories than they are expending. Imagine if this person needed to consume 400 grams of carbohydrates as part of meeting their caloric needs. Would relying solely on sweet potatoes, beans, and even fruits for carbohydrates be realistic? Probably not. That is over 4 pounds of sweet potatoes or just under 4 pounds of beans along with a whole lot of fiber, not including the vegetables one would also be eating. That amount of plant material will most likely result in gastrointestinal discomfort. Instead, along with some whole carbohydrates sources, white rice can easily be consumed in larger quantities without disrupting the digestive tract. 

The next individual is in a slightly similar situation, as they are having digestive problems. The GI issues are not due to consuming large quantities of carbohydrates, but instead, an underlying digestive disorder. It could be irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD). People experiencing digestive issues may benefit from reducing or limiting foods that are high in FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), and/or following a Specific Carbohydrate Diet (SCD), at least for a short time. These are carbohydrates that are fermented by bacteria in the large intestine, which is normal, but in conditions where there is an imbalance of bacteria (dysbiosis) or bacteria are in a location they do not belong, this can result in excessive gas production. This excessive gas can aggravate the GI tract, causing pain/discomfort. If you do suffer from GI issues, it is important to work with a professional who has experience helping those with GI problems and knowledge in how diet and lifestyle influence digestive conditions, such as a functional medicine practitioner. 

With that said, let us see the sources of carbohydrates one can include in their diet.

Sources of Carbohydrates

Starchy
Carbohydrates

Tubers:

  • Beets, Carrots, Cassava/Yuca, Parsnips, Potatoes, Sweet Potatoes/Yams, Taro, Turnips
Beans/Lentils:
 
  • Adzuki, Black, Cannellini, Garbanzo, Great Northern, Kidney, Pinto, Lentils (All Colors)

Grains:

  • Amaranth, Barley, Brown Rice, Buckwheat, Bulgar, Quinoa, Oats, Rye, Wheat

Starchy
Carbohydrates

  • White Rice – Best for those increasing calories or possibly with GI Issues

Fruit:

  • All Fruits

Non-Starchy
Vegetables

Leafy Greens:

  • Lettuce (Red & Green), Spinach, Kale, Chard (Rainbow & Swiss), Mustard & Collard Greens, Bok Choy

Non-Starchy
Vegetables

Cruciferous:

  • Cabbage (Red & Green), Napa, Broccoli, Brussel Sprouts

Root Vegetables:

  • Onions (All Colors), Garlic, Shallots

Others:

  • Artichokes, Asparagus, Bell Peppers (All Colors), Celery, Cucumber, Ginger, Green Beans, Mushrooms, Radishes, Tomatoes, Zucchini

How Many Carbohydrates Should You Eat?

Again, it depends. As a starting place, you can use your hand as a guide; however, more precise measurements/tracking may be necessary depending on what your goals are and the results using your hand yields. For now, be sure to Subscribe to download my free Create Meals with Real Food Infographic. 

You can aim for a cupped hand of carbohydrates at each meal along with a fist-sized portion of non-starchy vegetables at each meal. Now, if you are trying to lose body fat, you can try removing either a serving of carbohydrates and/or fat from one to two meals. 

Closing

You can eat carbohydrates and not get fat. You can even lose fat! There are things to consider when including carbohydrate-rich foods to your diet. For example, your individual post-prandial blood sugar response and the form in which you prepare and/or consume carbohydrates. If you tend to overeat, limiting the addition of fat and salt to carbohydrate-rich foods may be beneficial.

Depending on your goals and current digestive health status, you can choose from a variety of starchy and non-starchy carbohydrate sources. Using your hand as a portion guide can help, but it is not as precise as tracking and measuring food. So if you find the hand-size portion guide is not enough, more specific tracking, for a short time, may be necessary. 

Though carbohydrates are technically non-essential, as our body can create all the glucose our cells require, this does not mean you do not need to consume them. There are other benefits to eating carbohydrates other than them just being a fuel source, as carbohydrate-rich foods are a source of micronutrients (vitamins and minerals). Remember, the best diet/eating pattern is the one that you can sustain indefinitely. What is sustainable for you? Where do carbohydrate-rich foods fit in?

If you have questions, feel free to Contact Me. Additionally, if you have feedback for me or requests for topics you would like me to write about, you can Contact Me or email me directly at contact@jeremiahfarias.com.

Thank you for sharing your time with me! If you know someone who would benefit or simply enjoy this content, please feel free to share it with them. Enjoy your day!

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Sources:

Gropper, S.S. & Smith, J.K. (2013). Advanced Nutrition and Human Metabolism. Belmont, CA: Wadsworth.