Are Low-Carb Diets For Everyone?

In a world of fads, low-carb diets are very popular right now. Most know that cutting back on carbohydrates typically leads to weight loss. But are these type of diets for everyone?

Though we may want to believe so, the answer is no. Decreasing carbohydrates for too long can have long term consequences on your health. Three of the biggest include:

• Decreased testosterone production
• Decreased thyroid function
• Increased cortisol secretion

Each of these not only make it harder to maintain muscle mass but they also decrease metabolism and increase stress. This makes it difficult to sustain any weight loss or fat loss results.

Though it would be great to have a one size fits all approach, it doesn’t work like that. This begs the question “Who would benefit from a low-carb diet?”

When answering any question like this, it’s always best to look at the research to determine an appropriate answer. Based on the current body of knowledge, there are 3 groups of people who seem to benefit from low-carb diets. These include: those suffering from type 2 diabetes, obesity, or metabolic syndrome.

This isn’t an exhaustive list by any means. However, there’s been a lot of researched conducted on these particular groups. Let’s take a look at each one.

1. Type 2 Diabetes

Type 2 diabetes is a health condition that affects the way the body processes blood sugar. In a healthy individual, insulin is secreted after a meal to store blood sugar into specific tissues. Those suffering from diabetes secrete insulin, but their bodies don’t respond well to it (insulin resistance).

This creates a build up of sugar in the blood stream because insulin can’t do it’s job. One reason why diabetics can benefit from a low-carb diet is because carbohydrates increase blood sugar.

The goal of a diabetic is to lower and normalize blood sugar levels. By eating less carbohydrates, they can do just that.

One study compared a low-carb diet and a calorie restricted diet in 84 individuals with type 2 diabetes over a 24 week period (1). The results showed that the low carbohydrate group lost more weight (24 pounds total) and decreased their Hemoglobin A1c (1.5%) more so than the low calorie group. The authors also found that 95.2% of the low-carb group either reduced or eliminated diabetes medications.

2. Obesity 

Obesity is a health condition where excessive body fat increases risk of health issues. It presents a similar type of problem to diabetes.

Obese individuals often experience insulin resistance making obesity a precursor to diabetes. Because of this, eating less carbohydrates can be exactly what’s needed to help improve insulin sensitivity and lower weight.

One study had 132 individuals with severe obesity placed on either a low-carb or low-fat diet for 6 months (2). At the end of the study, the results were telling.

The low carb group lost 3 times as more weight as the low fat group. Not only that, but insulin sensitivity improved, fasting blood sugar decreased, and insulin levels dropped in the low-carb group. All of which improve body composition and health.

3. Metabolic Syndrome

Metabolic syndrome is group of conditions that increase risk of heart disease, stroke, and diabetes. The conditions include high blood pressure, high blood sugar, excess body fat, high cholesterol, and high triglyceride levels.

Most of these are the result of being sedentary, insulin resistant, and overweight. This makes a low-carb diet a helpful option to remedy these issues.

One study had 40 subjects with metabolic syndrome placed on either a calorie restricted low-carb diet or low-fat diet for a period of 12 weeks (3). By the end of the study, the low-carb group lost twice as much weight, 22.3 pounds to be exact. The low-carb group also decreased blood sugar, improved insulin sensitivity, increased HDL cholesterol (good cholesterol), and decreased triglycerides more so than the low-fat group.

Just like with our first two groups, a low-carb diet seems to improve many biomarkers of health and symptoms of metabolic syndrome.

But there’s one last group I want to quickly mention. Those who are more sedentary (i.e. work in an office all day) would also benefit from a lower carbohydrate diet.

Being sedentary is one of the first “pre-qualifications”, so to speak, of the conditions listed above. Consuming a lower number of carbohydrates, in general, could help to offset these risk factors before they become problematic. This could go a long way toward reducing disease and mortality risk.

Now, for an active individual with a normal weight, there’s no reason to be on a low-carb diet. Carbohydrates provide energy so we can perform specific activities. You’ll feel better and perform better when you have a balanced amount of carbs in your diet.

Wrapping Up

Low-carb diets can work wonders, when used by specific individuals. The thing to remember here is these individuals typically have some type of health condition like diabetes, obesity, or metabolic syndrome. This type of diet can aid in weight loss and improve several health markers like cholesterol, insulin, and blood sugar.

Those who are active, without health concerns, don’t need to fear carbohydrates. Sources like fruit, sweet potatoes, rice, and quinoa can all be part of a nutritious diet.

The best thing to do is experiment based on your body and goals. If limiting carbs improves the way your body looks and feels that’s ok. If not, that’s ok too. Either way, find what works best YOU not what the latest magazine or health show tells you to do.

References:

1. Westman EC, et al. The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutr Metab. (London), 2008.

2. Samaha FF, et al. A low-carbohydrate as compared with a low-fat diet in severe obesity. New Eng J Med. 2003. 348:2074-2081.

3. Volek JS, et al. Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids. April 2009, 44 (4). pp 297-309.