Low carb diets can make it hard to sleep. Image Credit: OlgaLepeshkina/iStock/GettyImages

Some studies show a link between low-carb intake and insomnia. Eating healthy complex carbohydrates, such as vegetables, appears to promote better sleep, but consuming unhealthy simple carbohydrates, such as foods high in sugar and white flour, seems to impair sleep.

Low-Carb Intake and Sleep Problems

An August 2014 study featured in the Journal of Occupational Health examined how dietary patterns affect sleep and found several correlations. A high intake of refined carbohydrates, such as noodles and confections, was associated with poor sleep quality, while a high intake of vegetables and fish was linked to good sleep quality.

The findings suggest that the type of carbohydrate consumption has a greater influence on sleep than the quantity of carbohydrate consumption.

In a February 2013 study published in the Journal of Epidemiology, researchers found further evidence of the importance of carbohydrates to sleep. A diet that involved less than 50 percent of caloric intake from carbohydrates was slightly linked to difficulty in staying asleep during the night in men.

A February 2015 study in the Journal of Sleep Research suggests a similar connection. Participants with sleep apnea and insomnia reported a lower carb intake than those who didn't have sleep disorders.

The Mediterranean diet, an eating plan that emphasizes healthy carbohydrates, such as fruits, vegetables and whole grains, is associated with a lower risk of insomnia. A 2018 study published in the journal Sleep found participants who followed the diet more closely experienced fewer symptoms of insomnia and a longer sleep duration.

This eating plan is also linked to a lower risk of obesity, states an April 2018 study published in Nutrition and Diabetes. In view of the benefit, the Mediterranean diet is a good option for those who have trouble sleeping while dieting.

Read more: Why the Mediterranean Diet Is Ranked the Best for 2019

Keto Diet Adverse Effects

As described by the Cleveland Clinic, the keto diet is a weight-loss plan that severely restricts carbohydrate consumption to about 5 percent of the daily caloric intake. Approximately two to seven days after embarking on the diet, people experience a cluster of symptoms called the keto flu or carbohydrate withdrawal. Difficulty sleeping is one of the signs, but Harvard Health Publishing lists other indicators like fatigue, nausea, headache, irritability, foggy brain and constipation.

A March 2019 study published in StatPearls says the symptoms of keto flu usually disappear in a few days. Drinking plenty of water and getting enough electrolytes can help reduce some of the signs.

While the keto flu isn't cause for alarm, the possible long-term effects of the diet are concerning, notes the StatPearls study. They include kidney stones, low protein and accumulation of fat in the liver, as well as vitamin and mineral deficiencies.

Although the keto diet produces weight loss in the short-term, the benefit isn't sustained over a long period. In addition, the StatPearls study warns that research shows the diet has serious complications like electrolyte disturbances, low blood sugar and dehydration that require emergency treatment. Anyone following the keto diet should be under medical supervision.

Low-Carb Diet Adverse Effects

The Mayo Clinic reports that sudden and dramatic reduction of carbs in the diet produces adverse effects. These include weakness, headaches, bad breath, skin rash, fatigue, muscle cramps, constipation and diarrhea. Long-term restriction may lead to nutrient deficiencies, gastrointestinal disorders, bone loss and an elevated risk of chronic disease. Low-carb diets aren't recommended for preteens and teenagers because they need the nutrients found in fruits, vegetables and whole grains.

Severely restricted carb diets are also not advisable for people who exercise regularly, says Rush University. When you eat carbohydrates, any that aren't used immediately for energy are stored as glycogen in the muscles. During physical activity, the body first utilizes glycogen as a source of energy. Once this reserve is used, protein in muscles is broken down for fuel. After a few months, this can result in slowed metabolism and other adverse health consequences.

As with the keto diet, the long-term effects of any low-carb diet have the potential to pose grave dangers to health, states an April 2019 study published in the European Heart Journal. The authors said people on these eating plans have a higher likelihood of premature death due to coronary heart disease, stroke and cancer. Study participants with the lowest carbohydrate consumption had a 32-percent higher risk of all-cause death compared to those with the highest carbohydrate consumption.

The study explains that consumption of animal protein, particularly red meat and processed meat, is tied to a raised cancer risk. Aside from the increased intake of saturated fat, such diets are low in fruits, fiber and health-promoting phytochemicals. The study concludes that the diets aren't safe.

How to Choose Carbs

The Harvard T.H. Chan School of Public Health says the type of carbohydrates eaten is more important than the amount. Healthy choices are those unprocessed or minimally processed, including fruits, vegetables, whole grains and beans. Examples of whole grains are brown rice, oats, barley and breads made with 100-percent whole-wheat or whole-grain flour. These foods are plentiful in vitamins, minerals, fiber and phytonutrients.

Conversely, refined carbohydrates are unhealthy choices, states the T. H. Chan School. These involve white rice and baked goods made of white flour such as cookies, cakes, crackers and white bread. They also include soda, candy and a host of processed foods that contain added sugar and corn syrup, says the United States Department of Agriculture.

Read more: How Refined Carbs Are Worse Than Other Carbs

Honey, especially raw, unfiltered varieties, has antioxidant, antimicrobial and anti-inflammatory properties. The positive effects are associated with various health benefits such as alleviation of coughs and promotion of wound healing, notes an April-June 2017 study featured in Pharmacognosy Research. However, like table sugar, honey raises blood sugar levels.