Low-carb diets have been around for decades – from Atkins and South Beach to Paleo and Whole30. They can be great for losing weight, but it’s necessary to be aware of the cons as well as the pros.
When people want to lose weight fast, they may opt for a low-carb diet to jump-start the weight loss process. But when done incorrectly or if the diet is too restrictive, it can cause nutritional deficiencies and health risks many dieters may not know about.
If you’re considering a low-carb diet, it’s essential to talk to a certified dietician or doctor so that you can understand what will and won’t work for your body and situation. Knowing the difference between low-carb diets and keto diets – and which is better for you in the long run – is just the tip of the iceberg, but arming yourself with this type of information directly from a specialist will help you reach your desired weight goals without risking your health.
Per the Dietary Guidelines for Americans, the average person should be consuming 45-65% of their total daily caloric intake from carbohydrates, as part of a healthy, balanced diet.1 Although there is no strict definition of what constitutes a low-carb diet, most experts accept that “low-carb” means less than 100-150 grams of carbohydrates per day.
Low-carb diets tend to have more flexibility than ketogenic – or keto – diets. The Atkins diet, for example, requires severely restricting your carb intake during the first phase. But as the diet progresses, the restrictions become more and more lenient, allowing you to gradually add carbs back into your diet as your body allows.
The keto diet, on the other hand, doesn’t allow for “cheat days.” To achieve ketosis and stay there, you have to consume 20 grams of carbs or less per day. Let’s put that into perspective: one medium-sized apple has about 20-25 grams of carbohydrates. A slice of bread has about 15-20 grams.
So, being on a keto diet means you have to significantly cut down on grains, fruits, dairy, and other important nutritional foods. Not only that, but you have to consistently consume this low amount of carbs to maintain ketosis.
There’s no denying that low-carb diets produce fast results, but these diets are good for more than just weight loss.
In the 1920s, ketosis was introduced as an alternative to anticonvulsant therapy for children with epilepsy. In fact, some still use it for this purpose today. It wasn’t until the early 2000s that the keto diet gained traction as a means of weight loss.
Emerging research also shows that the keto diet can improve blood sugar and HDL cholesterol levels. According to anecdotal evidence, ketosis can also improve mental clarity, reducing “brain fog” when the dieter takes adequate steps to minimize symptoms of the ‘Keto flu.’
Though it’s not for everyone, there is some merit to following a low-carb diet. The keto diet, however, is risky.
The biggest concern with the keto diet is the lack of research on long-term, sustained ketosis. Like most highly-restrictive diets, the keto diet is not easily sustainable over long periods of time. This leaves researchers without sufficient test subjects, as any registered dietician aware of the risks will not green-light a long-term keto diet study.
This unsustainable nature can also lead to a higher risk of “yo-yo dieting,” where the dieter repeatedly switches between dieting and normal eating. This back-and-forth takes a significant toll on the body and can lead to increased mortality rates.2
Although the keto diet does yield desired results – that is, losing a lot of weight in a short amount of time – losing more than 1-2 pounds per week can produce adverse health effects. Aside from the health risks, research also shows that the quicker you lose weight, the more likely you are to gain it back within the year.
While following a low-carb diet can help you reach your weight loss goals, it can be dangerous if not done properly.
Because low-carb diets require you to cut back on many fruits, vegetables, dairy products, and grains necessary for optimal health, those following a low-carb diet may experience nutritional deficiencies. Additionally, drastically changing your carbohydrate intake can cause headaches, weakness, fatigue, and GI distress. That’s not to mention the possible long-term effects of which we’re not yet aware. Before going on a low-carb diet, it’s important to know the risks involved to determine if a low-carb diet is right for you.
Though long-term low-carb dieting is not recommended due to the lack of research, a short-term plan can be effective. Those wanting to jump-start the weight loss process, cut back on added sugars, and kick unhealthy eating habits may benefit from a low-carb diet.
Consult your healthcare practitioner or a registered dietician to help you assess if a low-carb diet – or any diet – is right for you. A licensed professional can help you determine what would be safest and most appropriate for your body and overall health.
Low-carb diets have been trendy for decades, and they’ll likely continue to be so for years to come. And while they do show results, knowing the pros and cons of low-carb dieting can help you lose weight while staying healthy and keeping your body safe. Talking to your doctor or dietician about your options can help you decide which low-carb diet would work best for you, so you can lose weight without sacrificing your health.
1 U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015 – 2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at https://health.gov/our-work/food-and-nutrition/2015-2020-dietary-guidelines/.
2 Oh, T. J., Moon, J. H., Choi, S. H., Lim, S., Park, K. S., Cho, N. H., & Jang, H. C. Body-Weight Fluctuation and Incident Diabetes Mellitus, Cardiovascular Disease, and Mortality: A 16-Year Prospective Cohort Study. The Journal of Clinical Endocrinology & Metabolism, 104(3), 639-646.