The Importance Of Carbohydrates
Carbohydrates seem to get a bad rep these days. With more and more influencers and nutritionists promoting kept and Paleolithic styles of eating, carbohydrate seems to be the first to go. Why is that? Let's start by breaking down what a carbohydrate really is:
A carbohydrate by definition is a group of organic compounds found in living tissues including sugars, starch, and cellulose. Carbohydrates are the primary energy source for the body. Besides giving you energy, they are important for brain regulation and many bodily functions.
There are four pathways glucose can be used up by the body:
Converted to energy
Stored as glycogen in liver and muscle tissue
Made into fat in the liver (lipogenesis)
Goes into the pentose phosphate pathway (required to produce ribose which is used to make DNA & RNA)
Depending on how you current energy state, (in a caloric surplus or deficit), what kind of exercise you engage in, or if you are fasted versus in a fed state can determine which pathway glucose is used by the body. When you are in a fasted state (no food for 12-18 hours) your body goes through glycogenolysis (breakdown of glycogen via liver and muscle) and gluconeogenesis (formation of glucose from non carbohydrate sources- lactate, pyruvate, and amino acids). When you have not consumed carbohydrate or protein for longer than 24 hours, your glycogen is depleted and the body starts breaking down amino acids from muscle tissue and ketones start to form. This may lead to muscle loss unless consuming a very high amount of protein and fat and can lead to major dips in exercise performance and cognitive function.
So why is this important?
Thyroid Function
Carbohydrates are very crucial for healthy thyroid function. Low carb diets have shown to decrease thyroid function by inhibiting the conversion of T4 (inactive form) to T3 which is the active thyroid hormone. If you struggle with hypothyroidism, a low carb diet is not desirable.
Athletic Performance
If you are someone who exercises most days of the week, having ample carbohydrates throughout the day will aid in performance, energy, and promote recovery. Yes you can eat all the protein in the world, but if you are eating more protein than you need and too little carbs, your body is just going to turn that extra protein into carbs via gluconeogenesis (see above). So might as well make it easier on your body to just fuel it properly in the first place.
Female Reproductive Health
Ladies, I'm talking to YOU! We are not as resilient when it comes to dieting. Our bodies recognize when its being underfed really fast and if it thinks its not getting enough food, your ability to reproduce gets shut down.
Carbohydrates supports your HPA axis which is the communication between the central nervous system and the endocrine system. A lot of women who diet for long periods of time or go super low carb tend to lose their monthly cycle as it disrupts your hormones. Leptin is a hormone that circulates through your body assessing your energy availability. Your fat stores represent a vital component in your body’s energy balance and reproductive function is dependent on energy availability. So by eating too few of calories and/or carbohydrates you are signaling to your body that its under stress. (1).
Lower leptin levels = too much stress = increased cortisol = goodbye menstrual cycle
Read more about that in this post.
Sleep
Carbohydrate stimulates insulin, which drives these other amino acids into cells and thus has the opposite effect, making tryptophan more available (2). Higher glycemic carbs are more effective than low-glycemic carbs before bed to increase serotonin, tryptophan and GABA (relieving anxiety, stress, and improving mood). However, when combined with complete protein, tryptophan has a decreased ability to synthesize serotonin and melatonin. Having some starch before bed may increase your quality of sleep! WHO KNEW?!?!
Fiber
It shocks me that most Americans do not meet the recommended daily fiber amount (25-35g a day). Fiber is a non-digestable carbohydrate naturally found in plants. There is soluble and insoluble fiber. Soluble fiber add bulk to your stool and insoluble fiber "makes you go faster" to put it nicely. You need both. But consuming too little or too much can cause a lot of havoc on your digestive track. Fiber is also crucial because it binds to bile acids, cholesterol, fatty acids, and some minerals. If you are just eating protein and fats all day long without your friend fiber, you may be spending extra time in the restroom.
These are just a few of the many reasons carbohydrates are good for the body. If you are stressed out, not sleeping at night, lost your period, have trouble going to the bathroom, eating more quality carbohydrates can be really beneficial for you.
It seems as though people fear carbs because they believe it leads to weight gain.... which is false. Over consumption of ANY nutrient can lead to weight gain, even if you ate all your calories for the day in just vegetables. A lot of people also under estimate how much their bodies actually need so they eat less, slowing down the metabolism for the long run. If you eating a restrictive diet your body goes into a "starvation mode". When in starvation mode, your body wants to store the energy you give it because it's afraid of not getting enough in the future.
Also, it kills me when people say “fruit has too much sugar”.... Fruit is SO healthy! Yes, it does have naturally occurring fructose but they are full of fiber, vitamins, and minerals. All of those vitamins, minerals and antioxidants in fruit fight off nasty infections and diseases! Fruit intake can lower your risk of heart disease, diabetes, and stroke (3).
No food is bad. Instead, focus on everything in moderation instead of extremes.
References
Herrera, C P, et al. “High-Glycaemic Index and -Glycaemic Load Meals Increase the Availability of Tryptophan in Healthy Volunteers.” Current Neurology and Neuroscience Reports., U.S. National Library of Medicine, June 2011, www.ncbi.nlm.nih.gov/pubmed/21349213.
“Fresh Fruit Consumption and Major Cardiovascular Disease in China | NEJM.” New England Journal of Medicine, www.nejm.org/doi/10.1056/NEJMoa1501451
22. Liu S, Willett WC, Stampfer MJ, et al. A prospective study of dietary glycemic load, carbohydrate intake, and risk of coronary heart disease in US women. Am J Clin Nutr. 2000;71:1455-61.
Greunke. “Females, Carbohydrates, and Hormones.” The Paleo Diet - Robb Wolf on Paleolithic Nutrition, Intermittent Fasting, and Fitness, 19 Feb. 2014, robbwolf.com/2014/02/20/females-carbohydrates-hormones/.
