Due to all of the low carb information being tossed around in the last several years, it has become more and more prevalent for new clients to attempt to completely eliminate carbohydrates in the hopes of losing weight. The truth is you absolutely need glucose for normal body functioning, and eating carbohydrates is the easiest way for this to happen. While it's true that you can make glucose from protein or fat, unless you have a clear reason for eliminating carbohydrates from your diet, it's best to include them. Let's take a look at why that is.
As mentioned above, we need glucose to live. Whether that's from a potato or converted from a protein, it's an absolute necessity. For instance, the brain requires about 130g of glucose per day (1). Outside of our organs requiring carbohydrates, they also provide us with faster-acting energy. Think about activities lasting somewhere in the vicinity of 15 seconds to 2 minutes, such as a sprint. And, many people just function better with some carbohydrate intake. If you've ever cut most out of your diet for a period of time, there's a good chance your were absolutely miserable.
There are some hormone changes that can occur from drastically reducing your carbohydrate intake. Effects such as decreased testosterone, decreased estrogen, decreased progesterone, increased cortisol, increased LDL-cholesterol concentrations, and irregular periods have been shown in several studies (2, 3, 4, 5). Granted, the studies were comparing ketogenic diets versus non-ketogenic diets, but it still can explain some of the effects from very low carbohydrates. A ketogenic diet is one in which carbohydrate intake is so low that the body begins using ketones (proteins) as fuel rather than carbohydrates.
The exact amounts of carbohydrates people intake will vary greatly depending on several factors including body size, amount of lean mass, the activity level, age, genetics, and preference, to name a few. In general, though, 1 cupped handful of healthy carbs for women and 2 cupped handfuls for men are recommended to start with. By healthy carbs, I'm referring to foods that are higher in fiber, which also are slower-digesting. This is completely doable by eating:
Legumes and beans
Some whole grains (depending on your goals)
It can't be stated strongly enough, the type of carbohydrate you eat is crucially important. Not all carbs are created equal. For instance, eating an apple is very different from eating a piece of cake. An apple contains fiber (both soluble and insoluble), plenty of nutrients, and will keep us much more satiated than cake, which is devoid of nutrients, stimulates our appetite, causes a spike in insulin (a storage hormone), and leads to greater blood sugar fluctuations. As much as possible, we're looking to get more of the healthy type carbohydrates. A great rule of thumb is that if it comes out of a box, it's not a great source.
It's best not to start out by eliminating carbs altogether in your weight loss journey. That is most likely too challenging and usually unnecessary. Plus, there are valuable nutrients in healthy carbs that you should be getting regularly.
1. Fuhrman, Joel (1995). Fasting and Eating for Health: A Medical Doctor's Program for
Conquering Disease. New York, New York: St. Martin's Press
2. Johnston CS, et al. (2006). Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets. American Journal of Clinical Nutrition, 83(5), 1055-61.
3. Lane AR, Duke JW, Hackney AC. (2010). Influence of dietary carbohydrate intake on the free testosterone: cortisol ratio responses to short-term intensive exercise training. European Journal of Applied Physiology, 108(6), 1125-31.
4. Brinkworth GD, et al. (2009). Long-term Effects of a Very Low-Carbohydrate Diet and a Low-Fat Diet on Mood and Cognitive Function. Arch Intern Med, 169(20), 1873-1880
5. Soenen S, et al. (2012). Relatively high-protein or ‘low-carb’ energy-restricted diets for body weight loss and body weight maintenance? Physiol Behav, 107(3), 374-80.