5 Things to Know About Low Carb Diets

by Joanne Perez, MS, RDN, LD
Low Carb Diet

Whether it’s Atkins, South Beach, Paleo or the hot Keto Diet, low carb diets are built around the idea that carbohydrates are bad. But, the thing is that many people don’t really understand carbohydrates. And when you limit them, you are robbing your body of vitamins, minerals, phytochemicals and fiber that are essential for good health.

There are two types of carbohydrates and our bodies need both. Complex carbohydrates are generally those found in whole grains and are comprised of a longer series of sugars which take more time for the body to break down and use as energy. In addition, these carbohydrates tend to be high in fiber, a substance that is harder for the body to breakdown and absorb. The result of eating whole grain carbohydrates is a more consistent release of sugar into your bloodstream to keep you energized all day.

 Simple carbohydrates are made of simple to digest, basic sugars that your body uses for energy immediately. They give you a rush of energy. You find simple carbohydrates in most processed foods, sweets and refined complex carbohydrates. They might not provide a ton of nutrition, but they give use other benefits, such as satisfaction and enjoyment with eating.

 When you eat low carb, you not only run the risk of hurting your body physically, but also mentally. Plus, eating low carb may affect your social life as you have to watch everything you put in your mouth.

Here are 5 things you need to know before you jump on the low carb craze:

1. Carbs Are More Than Bread and Pasta

Most people don’t even know what foods are considered carbohydrates. Sure, everyone knows about bread, pasta and rice, but why do many low carb diets limit fruit and even vegetables. It’s because fruits and vegetables are actually simple carbohydrates. The big difference here is that they function more like whole complete carbohydrates. They tend to be higher in fiber, which changes the way the body breaks down their sugar. Fruit and vegetable sugars are broken down and absorbed more slowly. If you add some protein, you can really slow down the absorption to give you sustaining energy.

2. Low Carb Diets Are Not Healthy

Our brain and muscles use carbohydrates as a primary source of energy, but most carbohydrate-rich foods offer a lot more benefits. Many are high in fiber which is important for keeping our digestive system healthy and making us feel full and satisfied between meals. Plus, they contain many of the B-Complex vitamins that are essential for many functions in the body. If you are not eating carbs, you are starving your brain which may result in irritability, trouble concentrating and extreme fatigue.

Research shows that low carb diets may improve some metabolic markers, including insulin sensitivity and blood lipids, but they don’t reduce the risk of cardiovascular disease or overall mortality. A 2013 meta-analysis indicated that low carb may increase your overall mortality rate (1). Low carb diets are hard to maintain so any benefits are usually short-term.

We don’t know the full effects of being on a low carb diet long-term, but we do know that prolonged depravation of carbohydrates forces yourliver to be exposed to extra stress as it is forced to assist with manufacturing glucose from fats and proteins, there is an increased risk of potentially toxic amounts of ammonia being produced as proteins are converted into glucose, your immune system becomes compromised and your body loses the ability to produce compounds called glycoproteins, which are vital to cellular functions.

3. Low Carb is Not A Magic Weight Loss Method

If you cut out a major food group from your diet, then you are most likely going to decrease your overall food intake. But, a study in New England Journal of Medicine found that although low carb produced more significant weight loss at 3 months, the loss at 12 months was insignificant (2). And the rapid weight loss is due to loss of water weight. When you eat low carb, you deplete your glycogen stores which store water in addition to glucose. So, when there is no glucose, the water is flushed out. A 2017 study showed that people on the ketogenic diet who had rapid weight loss also had rapid weight regain (3).

It is widely known that whole grains and high dietary fiber intake have several health benefits, including better blood glucose control and a healthier GI system, but 2017 study published in the American Journal of Clinical Nutrition showed promising results concerning whole grains and resting metabolic rate. Researchers found that participants of the study who ate whole grains had an increase in their resting metabolic rate and a reduction in the number of calories that are retained during digestion (4).Their bodies became more efficient at burning calories while doing nothing. Unlike the quick fix you might get from eating low carb, whole grains may actually help with long-term weight management.

4. Low Carb Will Result In Muscle Loss

Muscle growth requires insulin which is produced when you eat and digest carbohydrates. Also, if you don’t have full glycogen stores, your body will turn to muscle for energy. In addition, less muscle means, means less metabolically active tissues so you could have a decrease in your metabolic rate.

5. Depravation Leads to Bingeing Behaviors

The research is clear that restricting foods leads to overeating. In response to not having enough energy (carbs), our brain will secrete a chemical, neuropeptide Y (NPY), to make you think about food.  NPY increases your desire to eat, delays satiety and simulates food intake especially carbohydrates, your brain’s main fuel source. And because NPY delays satiety, our bodies crave lots of carbohydrates which results in bingeing.  Low carb will actually cause you to crave carbs which is why eating this way is not sustainable for most people.

Don’t for the low carb hype. Diets don’t work and removing entire food groups from your diet may have lasting harmful effects. The best approach is to eat and enjoy a balanced diet that includes all foods while listening to your body’s hunger and fullness cues.

 *Very low carb diets are often used to help control seizures in people with epilepsy. People using this type of diet for a specific, diagnosed medical condition are not the intended audience of this article.



Noto H, Goto A, Tsujimoto T, Noda M. Low-carbohydrate diets and all-cause mortality: a systematic review and meta-analysis of observational studies. PLoS One. 2013;8(1):e55030.

Foster G, et al. A Randomized Trial of a Low-Carbohydrate Diet for Obesity.

N Engl J Med2003; 348:2082-2090

Kosinski, Christophe, and François R. Jornayvaz. “Effects of Ketogenic Diets on Cardiovascular Risk Factors: Evidence from Animal and Human Studies.” Nutrients 9.5 (2017): 517. PMC. Web. 8 Aug. 2018.

Karl, J., et al. Substituting whole grains for refined grains in a 6-wk randomized trial favorably affects energy-balance metrics in healthy men and postmenopausal women. The American Journal of Clinical Nutrition, Volume 105, Issue 3, 1 March 2017, Pages 589–599

Article contributed by Joanne Perez, MS, RDN, LD. See more posts like these

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