The nuts and bolts of nutrition? Our bodies require proteins, carbohydrates, and fats to function. It’s that simple.

The balance is of these 3 macronutrients is really important—every meal and snack needs to contain all of them. For example, we need proteins to carry fat in our blood. If you eat too much fat or too many carbohydrates that get converted into fat, you will need more protein to move that fat in your blood around. Carbs provide good vitamins and minerals that fats and proteins may not. Think of macronutrients as the three branches of our government: each does its own job as well as act as a check and balance for the others.

Why do we need to eat carbohydrates?

Life is carbohydrates! So many of our food traditions involve carbs: bread with dinner, popcorn at the movies, a glass of wine with an evening meal, French fries, pepperoni pizza, or a peach right from the tree. Even the phrase “American as apple pie” is about carbs.

Carbohydrates and fats release water and carbon dioxide when converted to energy—basically, they’re clean energy. Without ample carbohydrates, we must burn either fat or break down muscles to meet our energy needs. If the body’s digestive system is dysfunctional, inadequate fat burning may produce something called ketones. Proteins produce ammonia and keto acids as byproducts. Some of byproducts can be pretty tough on the body, especially the brain. But by using carbohydrates for the majority of energy, we can use proteins and fats for their other intended purposes.

What are carbohydrates?

Carbohydrates encompass a pretty diverse group of food. Still, as different as they appear, all are all made from carbon atoms plus water. 

There are only 3 sugars: glucose, fructose, and galactose of which we only use glucose. The other types are used by our gut bacteria for energy. Monosaccharides and disaccharides are considered to be “simple” sugars because they are easily broken down and able to provide quick energy. 

• Monosaccharides: Single-sugar carbs 
• Disaccharides: Carbs that are a combination of 2 sugars. Sucrose is a combination of glucose + fructose, lactose is glucose + galactose, and maltose is glucose + glucose. 

There are also more “complex” sugars. Depending on the number of sugars they contain, each perform different functions.

• Oligosaccharides are carbohydrates that contain 2 to 10 sugars. They reach the large intestine intact; once there, they act as prebiotics for our gut cells. Oligosaccharides also help with cell recognition and cell adhesion, functions that allow white blood cells to hold onto any invaders they encounter.
• Polysaccharides contain more than 10 sugars and are known as “complex” carbs. Since they are digested more slowly, they provide a source of extended energy. Polysaccharides are starches, fibers, and glycogen (a string of stored glucose molecules).

What about sugar? 

Our digestive tract doesn’t respond to all carbohydrates in the same way, some are used for energy and others support our gut bacteria, or microbiome.

For example, starches and fibers both contain hundreds to thousands of linked monosaccharides—starches are easily broken down into simple sugars, but fiber is not. Fiber can also trap starches to prevent them from being digested, creating something called resistant starch. RS feeds our gut bacteria so that they in turn create the short-chain fatty acids that keep our gut cells healthy. RS improves blood sugar and insulin response, lowers cholesterol and triglycerides, increases satiety, and reduces fat storage.

Sucrose

It probably won’t surprise you on how much sugar we consume. According to the USDA’s “Dietary Assessment of Major Trends in U.S. Food Consumption, 1970-2005,” sugar consumption increased to 142 pounds per person, not including fruit. To put that into perspective, for a 2,000-calorie daily diet, they recommend sugar consumption not exceed 8 teaspoons of sugar per day—less than 32 pounds per year.

In 2005, Americans consumed around 30 teaspoons of added sugars and sweeteners per person per day, which is 4 times the recommended amount. Given the trend, I doubt that the current data will show any decrease in consumption.

Sugar starts to break down in the stomach and requires the release of insulin to be absorbed completely. Excess glucose is stored as glycogen for later use.

If you eat too much of any type of sugar, it ends up in the large intestine, where bacteria and yeast thrive on it, creating gas, cramping, and spasms. With so much sugar in the large intestine, water is drawn in to dilute the sugar, which then leads to diarrhea.

Fructose 

Fructose is found in honey, fruits, and some vegetables.

It’s processed differently from glucose. Fructose is broken down in the liver and doesn’t cause a release of insulin. Therefore, the metabolic rate of fructose in the liver is at least twice as fast as that of glucose. Since we don’t need that much sugar that quickly, excess sugar is stored as fat. This is the most likely reason for the increased triglyceride levels found in folks who eat a “normal amount” of sugar. Additionally, of insulin’s functions is the regulation of hunger through ghrelin (hunger) and leptin (satiety) hormones. Fructose does not seem to affect these hormones, so we ae able to keep eating without feeling full.

In order to get a feel for how much fructose you are consuming (and other macronutrient info), check out the USDA’s Nutrition Database .Make sure you select the full report to see the types of sugar.

Dr. Mercola, DO, recommends limiting total fructose (fruit included) to below 25 grams per day, with a max of 15 grams from whole fruit. 

High-fructose corn syrup (HFCS)

HFCS is an sweetener that became popular in the 1970s. It is different than corn syrup which is strictly glucose. HFCS is a combination of fructose and glucose. 

It is made in a multistep process that begins by taking cornstarch and hooking it to fructose. It is then blended with glucose to mimic sucrose. HFCS is extremely stable in acidic foods such as cola, meaning that HFCS creates a more consistent flavor. Manufacturers like HFCS since it is easier to use in products and is a cost-effective ingredient.

There is a lot of controversy regarding the safety of HFCS. Since I am not a doctor or PhD, I am obviously not an expert, but here is my 2 cents. First, corn is closely related to gluten and eaten in copious amounts and can lead to inflammatory conditions in the body. Second, we are eating a lot of it. From 1970 to 2005, the availability per capita of corn sweeteners increased by 387%, while the use of sucrose, refined cane sugar, and beet sugars declined by 38%. During that same period, the use of HFCS grew from 3 to 76% and chronic diseases appeared more prevalent.  A lot of fructose is not a good thing.

Lactose

Milk sugar or lactose is galactose and glucose joined by a special bond which requires an enzyme called lactase to break it down. In contrast to the enzymes that we use to break down other disaccharides, our body’s production of the lactase enzyme is limited, which in turn limits the amount of lactose you can digest. 

Have you heard that you shouldn’t drink milk when you have a stomachache? That’s because when your gut is inflamed, lactase production decreases, which causes the sugar to go undigested into the large intestine. This could lead to gas, bloating, or an explosive session in the bathroom. If you are lactase-deficient, you might still be able to eat cultured dairy products such as sour cream, yogurt, and aged cheeses since bacteria and yeast help to digest the lactose in those products.

According to a 2006 edition of Nature, Asians, Africans, and Jewish adults do not produce lactase after childhood, but some adults (mainly Europeans) have a genetic mutation that allows production through adulthood.

Many folks believe they are lactose-intolerant, however, it’s usually not an issue with an enzyme that’s causing the problem—it’s the protein contained in dairy. An elimination diet can help pinpoint this.

Alcohol sugars like sorbitol

Many folks ask me about other types of sugars. One of those is sorbitol, which is a common “low-calorie” sweetener used in gum and candies. It is about 60% as sweet as sucrose. 

Sorbitol is a sugar alcohol produced in our bodies from glucose and then converted to fructose by a few of our tissues. It’s not broken down in the small intestine, so it ends up in the large intestine undigested. According to the FDA, more than 40 to 50 grams of sorbitol can cause stomach pain and diarrhea— when the amount of sorbitol ingested exceeds the capacity of the intestine to handle it.

How do carbohydrates affect my blood sugar?

You may have heard you should stay away from watermelons and carrots because they are high-glycemic foods, which is another way of saying those foods are known to cause blood sugar levels to rise too high. But do they?

Glycemic Index

The glycemic index measures how 50 grams of the carbohydrate in a food affects blood sugar levels– as compared to the blood sugar levels of 50 grams of glucose or white bread. Basically, the higher the number, the higher the blood sugar response. Low glycemic index foods are considered to be 55 or less and high-glycemic index foods score 70 or above.

There is confusion about glycemic impact since this data was first released in 1995. For example, glucose is rated 100, whereas carrots can range anywhere from 92 to 20 (in the oldest data) to 32 to 16 (in the latest data). As you can see from that broad range, carrots could theoretically raise blood sugar pretty high in 1995 yet be perfectly fine to eat in 2008. How can that be right? Turns out that when the 1995 data was crunched, only 5 test subjects were evaluated. Such a small number of subjects is probably not a smart way to formulate a recommendation for an entire population.

When reviewing USDA databases, reference points seem to have a different value for the same food. The difference might have to do with the variety or species of the food or possibly its starch accessibility based on how it is  prepared.

Glycemic Load

Another way to determine a food’s response is looking at its glycemic load.

It also represents a food’s effect on blood sugar, but it takes into account the amount of that food you would have to eat. For example, to consume 50 grams of carbohydrates of raw carrots (fiber not included), you’d have to eat 6 to 8 carrots, about 5 cups. Now, that may be okay in a super large smoothie that we share with friends,, but we normally we aren’t going to sit down and eat 1.5 pounds of carrots at a time.

So the glycemic load uses the glycemic index value and multiplies it by the actual number of carbohydrates in a serving—in this case, 100 grams of the actual food. For raw carrots, that would be about a cup, which some folks might still have a hard time eating. High-GL foods have a value of 20 or more and low-GL foods score less than 10, making the blood sugar response from carrots at 2 almost non-existent. 

Basically, the more fiber a food contains, the lower the glycemic load and the less impact on blood sugar. 

How much carbohydrates should I eat everyday?

Unfortunately, no simple answer. Many dietary experts are now recommending a ketogenic diet which limits carbs to less than 20 grams daily. This is the opposite of 30 years ago, when experts claimed that everybody should basically just eat carbs—up to 80% of our diet. 

Each type of diet has its place and is different for every individual. Those with hard to control blood sugar or immune issues may do much better with a strict keto approach. I like to meet in the middle when working with a new client at 50-100 grams of carbs per day. We then start to slowly reduce to see if we can achieve greater health benefits. But if someone has issues with breaking down or using fats, higher carb diets in the 100-150gram per day may be warranted.

What happens if we don’t eat enough carbs?

I have had a few clients not respond well to dietary changes at the beginning. Typically, when they avoided potentially inflammatory foods, they didn’t eat enough food to replace those calories and were consuming fewer than 1,500 calories per day with less than 50 grams of carbs.

To reduce carbs, it must be done slowly while the body learns to adapt to a higher fat intake. Folks who do not heed this advise may wind up with the “Keto flu”. Additionally, others are not able to absorb or utilize fats effectively find they must have a higher carb diet to maintain energy levels. 

According to Dr. Paul Jaminet, PhD, not having enough carbs may affect our immune system for some individuals, He states that neutrophils (white blood cells) are less able to kill infections like candida when ketones are present. I’m not sure about this, as low sugar diets are recommended specifically for Candida. Additionally, the immune system responds well to lower carbs diets  since it tends to help normalize blood sugar and  control inflammation. Just thought I would throw that out there for anyone who is having issues with a lower carb diet and immune issues.

One more caveat. If the carbohydrate content of the diet is too low, the body’s amino acids wind up having to supply enough glucose to keep blood sugar levels even and the brain fed. If we have to use proteins for sugar stability, we may be unable to use amino acids for their intended purposes (i.e., building and repairing tissues), and end up scavenging proteins from our gut, skin, muscles, etc.

What is the best diet?

We are all different. I like an anti-inflammatory, mild ketogenic diet with 20-25% protein, 20-80g carbs, and over 50% of daily calories supplied by fat. But this should be adjusted based on activity, biochemistry, lifestyle, etc. Please work with your provider to find the best approach for you.