Ten Scientifically Proven Benefits of Low-Carb Diets

Estimated reading time: 7 minutes

Public health guidelines generally focus on recommendations that guarantee adequate nutrition, vitamins, and minerals. Furthermore, they emphasize balancing calorie intake with physical activity.

Dietary guidelines usually recommend eating healthy foods like vegetables, fruits, whole grains, fat-free or low-fat dairy products, seafood, and to consume less sodium, saturated fats, trans fats, added sugars, and refined grains.

Ten benefits of a low - carb diet

However, when it comes to the individual, what is best in each case varies greatly. Hence, dietary recommendations have to be tailored to the individual needs.

Dietary recommendations have to take into account factors such as height, weight, BMI, body stature, waistline and metabolic function. Does the individual suffer from diabetes, high blood pressure, lipid problems, heart disease or obesity? Dietary recommendations have to be tailored to the individual needs.

Providing general advice about diet and health that applies to everybody is a very difficult task. As a physician, I have a very broad view when it comes to diet and nutrition. I am not a fan of a certain diet. Many people do very well on a balanced diet as suggested by the dietary guidelines.

However, I have doubts about the overemphasis on low-fat, as suggested by the guidelines. “Low fat ” has almost become synonymous with “good health”.

I have nothing against low-fat diets. However, I doubt that the emphasis on low-fat, low saturated fat, in particular, is based on good scientific evidence. Furthermore, I believe that the overemphasis on low-fat may have caused consumers and manufacturers to choose foods that may be potentially harmful and could have contributed to the so-called obesity epidemic and increased prevalence of type 2 diabetes.

A low-fat diet may be preferable for some individuals while other individuals may do better on a low carbohydrate diet. The fact that I may recommend a Paleo or an Atkins type diet for some people, does not mean that I am against whole grain or potatoes. Although  I recommend everybody to avoid simple refined sugars and junk food, I think complex carbohydrates, starches, and not least fiber can be a part of a healthy diet for many people.

As a cardiologist, I see many patients who are overweight or obesity. Many of them have what is called the metabolic syndrome. It is estimated that nearly one of every four American adults suffer from this condition. These individuals have an increased risk of developing type -2 diabetes and heart disease.

The metabolic syndrome is associated with increased waist circumference, elevated blood pressure, elevated triglycerides, reduced levels of HDL – cholesterol (the good cholesterol), elevated blood sugar (glucose) and insulin levels. Treating and preventing this condition is of huge importance for the community and a big challenge for health professionals.

For many years, I was hugely skeptical about recommending low carbohydrate, high-fat diets (LCHF) to patients with overweight or obesity. Like so many of my colleagues, I was afraid such lifestyle might elevate blood cholesterol and increase the risk of coronary heart disease.

However, during the last ten years or so, scientific studies have shown that LCHF diets may indeed be helpful for those suffering from overweight or obesity. They may not only help people lose weight, but they may also improve your general health in many ways.

There are now few years since I started educating patients with overweight, obesity or signs of the metabolic syndrome about the possible health benefits of LCHF. I have seen many of them having a great success with this lifestyle. Most have managed to improve their general health and modify their cardiovascular risk factors in a positive way. By this, I’m not saying that other methods don’t work, but I can confirm that LCHF very often works in real life.

There is much evidence suggesting that people with the metabolic syndrome suffer from carbohydrate intolerance, a phenomenon that is associated with high levels of insulin and insulin resistance. This implies an exaggerated glucose and insulin response to a given amount of carbohydrate ingested. Glucose uptake by muscles may be impaired which may help divert ingested carbohydrate to the liver where it is converted to fat. This may lead to elevated triglycerides and other lipid problems.

Let’s say you decide to give it a try. You decide to avoid refined sugars entirely, throwing candy and beverages out of the window. You also cut down on other types of carbohydrates, avoiding potatoes, bread, corn, pasta, and rice. Basically, the only carbohydrates you will eat are those found in vegetables and fruit, but you may want to limit them as well.

To provide the body with energy, you will increase the consumption of natural healthy fats. You will eat dairy fat, animal fat and plant-derived fat. You will avoid low-fat dairy products because they are usually rich in artificial sugar. Then slowly, later on, you start selectively adding carbohydrate to your diet, in the amount tolerated so that you will not start to gain weight again.

Just remember, before you do it, consult your doctor and ask for his advice because there might be individual issues that have to be addressed. Have baseline tests performed, let him or her check your blood pressure, blood sugar and blood lipids (total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides). In three to six months you can check these markers again for comparison.

Don’t forget to follow the advice of experts in the field or people who have experience, because there may be some pitfalls. For example, you may have to drink broth regularly because of the sodium loss that commonly accompanies LCHF diets.

What can you expect? How will this lifestyle change affect our health?  This is what is likely to happen following carbohydrate restriction. Keep in mind though, that there is individual variation, people do not all respond in exactly the same way.

Ten Scientifically Proven Benefits of Low-Carb Diets

1. You Will Lose Weight

Scientific studies and years of experience have shown that weight loss will occur on a LCHF diet. The amount of weight loss may vary between individuals and will also depend on how aggressive you are in getting rid of sugar and carbs.

2. Blood Sugar Will Improve

Studies have shown that low carbohydrate diets reduce levels of fasting glucose and glycated hemoglobin. This may be beneficial, in particular, if you have diabetes or prediabetes, which is quite common among individuals with the metabolic syndrome.

3. Blood Pressure Will Improve

High blood pressure is one of the strongest known risk factors for stroke and heart disease. Lowering blood pressure is therefore considered a very important step to lower the risk of cardiovascular disease. Studies indicate that LCHF diets lower blood pressure in individuals with overweight or obesity.

4. Triglycerides Will Improve

Blood levels of triglycerides have emerged as a very important risk factor for cardiovascular disease.  High serum triglyceride level is associated with abnormal lipoprotein metabolism, as well as with other risk factors including obesity, insulin resistance, diabetes mellitus, and lowered levels of HDL cholesterol. It has been shown in a number of studies that carbohydrate restriction lowers triglyceride levels significantly.

5. HDL Cholesterol Will Improve

HDL cholesterol is inversely related to both coronary heart disease and other cardiovascular disease mortality in both man and women. This means that low levels of HDL-cholesterol are associated with risk of heart disease. Carbohydrate restriction has been shown to increase blood levels of HDL-cholesterol.

6. LDL Particle Size Will Improve

LDL-Cholesterol particles exist in different sizes. On one hand we have the large, fluffy, cotton-ball like molecules, and on the other hand the small dense molecules. Many recent studies have looked into the importance of LDL-particle size. Studies show that people whose LDL-C particles are predominantly small and dense have a threefold greater risk of coronary heart disease. Furthermore, the large and fluffy type of LDL-C  may actually be protective. Studies indicate carbohydrate restriction positively affects particle size by reducing the number of very small and small LDL particles.

7. LDL Particle Number (LDL-P) Will Improve

Blood levels of LDL-P are strongly associated with the risk of cardiovascular disease and some studies indicate that LDL-P may be a stronger predictor of risk than the commonly used LDL-cholesterol. LCHF diets appear to significantly reduce LDL-P.

8. Insulin Resistance Will Be Reduced

Insulin resistance is common in individuals with the metabolic syndrome and is strongly related abnormal lipid profile. There appears to be an association between insulin resistance and cardiovascular disease. Studies indicate that carbohydrate restriction significantly lowers insulin resistance compared to a low-fat diet.

9. Insulin Levels Will Drop 

High levels of insulin are associated with insulin resistance. Hyperinsulinemia (high levels of insulin in the blood) appears to be an independent risk factor for coronary heart disease. Therefore, lowering insulin levels may be beneficial. Carbohydrate restriction has been shown to significantly decrease insulin levels.

10. C-reactive Protein Will Be Reduced

C-reactive protein (CRP) can be measured in blood and is a known marker of inflammation. CRP, in particular, high sensitivity CRP (hs-CRP) has been associated with cardiovascular risk. There is evidence that carbohydrate restriction lowers the level of CRP, which may indicate that LCHF diets can reduce inflammation.

17 thoughts on “Ten Scientifically Proven Benefits of Low-Carb Diets”

  1. Dr. Sigurdsson,

    This is a very interesting post that highlights the potential benefits of low carbohydrate, high fat diets (LCHF) for overweight and obese individuals. As someone who is very interested in healthy diet and lifestyle, when I ran into your post I was very much intrigued. I do, indeed, agree with your belief that the standard dietary recommendations do not factor in individualism and does not work for all of us. Like your personal successful experience through this particular diet, I have tried this too in the past and it was very much successful. Given my field of interest in dietary health, I have looked into many different types of diets, which could be a potential preventative for obesity or overweight. The ten benefits of low carbohydrate diets you’ve mentioned in your post has advanced my knowledge and given me confidence to endorse this type of diet in my future career as an educator in health. Even though you have indicated, “there is individual variation, people do not all respond in exactly the same way”, I believe that this diet definitely has a promising potential for becoming the healthiest diet people can start on to reach their health goals.

    Although low carbohydrate diet has many benefits, I wonder why this type of diet has not been centered in creating the dietary recommendations we have today? Could it be because of the potential energy loss that comes with the depletion of carbohydrates? I’ve also noticed that you have mentioned that this diet works well with overweight and obesity individuals, but this makes me question about other individuals like people with diabetes. You have provided with many studies that prove that this diet does change insulin resistance and levels–so wouldn’t this diet be suitable for diabetic patients as well? And even further, why wouldn’t this diet be good for other people? I would believe that this diet would be a good preventative diet plan for obesity, diabetes or any cases. Additionally, when you discussed about healthier diets for obesity individuals, I was personally surprised not to see any physical activity component mentioned in your post. I understand the importance of just the diet, but I would think physical activity is linked to obesity as much as the diet. I strongly believe that it’s not just diet that needs to be changed but the actual lifestyle that needs modification in order to make people healthier. For an example, I am from Japan. Japan has the least obesity rate, but our diets are full of carbohydrates and less in fat. I think the major contribution to Japan’s low rate of obesity is our diet but moreover our daily physical activity.

    • Mai Funaki. Thank you for your comment. You do touch on some interesting points concerning low carb, overweight, obesity and diabetes. It has certainly been suggested that carbohydrate restriction may be beneficial in type 2 diabetes. Here is an interesting overview that you might want to read: https://www.nutritionandmetabolism.com/content/5/1/9.

      I do agree with you about physical activity. I think it is an essential part of a healthy lifestyle and a key to physical and psychological wellbeing. The japanese experience is certainly interesting and proves that carbohydrates don´t necessarily make you fat. This may all depend on the type and amount of carbohydrates you consume. I do not consider carbohydrates to be bad, although carbohydrate restriction may be helpful in certain situations. Maybe the problem starts when you get fats and carbohydrates on the same plate. Could it be that moderation is more common in Japan than elsewhere? I also wonder whether obesity is becoming more common in Japan with the “westernization” of the diet.

      Thanks again for sharing your thougts.

    • Doubful. There is no “energy loss” on a LC/HF WOE. Rather, energy is increased, is more consistent and more readily available (since the body can much more readily access the massive “calories” stored in fat quickly for energy, something not available to people on “normal” diets who will “hit the wall” when sugar-energy runs out. For more, read this: https://www.meandmydiabetes.com/2011/04/14/steve-phinney-low-carb-preserves-glycogen-better-than-high-carb/.

      More likely, the real reason is MASSIVE DECREASERES IN REVENUES (profit) to lots of interested parties. Those include processed food makers (nearly all of which are carb-based), pharmaceutical and medical companies and grain-based agricultural concerns. Ever wonder how it is that these dietary recommendations are the responsibility of the Department of AGRICULTURE?! Huh? Shouldn’t that be “Health and Human Services”?! Major conflict of interest there.

  2. This article is very useful, i am happy to see a medical expert reporting on the benefits of a low carbohydrate and high protein diet. It is also very helpful to see some scientific thought being put behind the report and the analysis. I have been involved in coaching combat athletes, boxers and martial artists for almost 30 years and have also been a personal trainer working with body builders and strength athletes.
    I have always been an advocate for the use of Low carb/High protein for a number of reasons mostly though because this type of diet makes sense. I t is what a lot of kids were brought up on in the days of my grandparents (i am 42 by the way).
    Its just what my grandmother taught me to grow strong as a kid and also my old boxing coach taught me this method to make weight, stay energetic for intense training and stay strong and powerful.
    Simple as this: –

    Eat good meat, however i reccommend very lean cuts for those who wish to lose more weight at a faster loss then be less strict as the target weight is reached, contrary to popular beleif, some fat is good for you.
    Eat green and leafy vegetables, add extra virgin olive oil sparingly.
    Eat fish 3-4 times per week.
    Eat lots of citrus fruit, especially when cutting weight as snacks
    Eat pulses and beans at least once a day
    Eat eggs once a day
    Restrict bread, potatoes, rice, pasta and root veggies until the target weight is reached, then add in natural sources of complex carbs where possible, do it sparingly but remember greens are the best!

    I am so interested in this method of eating and other natural ways to manipulate the human system for optimum health and performance i have started a website http://www.lowcarbhighproteindiet.com.
    I will be adding more articles and refreshing this site in the coming weeks as i acquired it as it is with a view to using it to educate my athletes, my martial arts students and the general population where i can.

    • Lee, did you read the article?
      It is talking about a Low Carb High Fat LCHF diet not high protein. Big difference.
      There is absolutely no need to eat protein much above your needs.
      Fat is your fuel source not protein. That means eating fatty cuts of meat, full fat dairy, pour the olive oil on, eat all the eggs you like and NO pulses or beans, otherwise you have it fairly right.

  3. Dr. Sigurdsson,

    Do you have any advice for dealing with a doctor who is unreceptive to the idea of a LCHF diet? I am consistently told to “cut fat” and “stop snacking” (I don’t actually snack), “eat more whole grains” and “lose weight”… and then get scolded for “being noncompliant” when my blood sugar is elevated and my weight creeps up.

    Frankly, it’s beyond frustrating, to the point that I actively dread going to see my doctor for anything, including totally unrelated things like sinus infections or injuries. My doctor ignores all of my research, including studies I print out from the American Journal of Clinical Nutrition, the National Institute of Health. Johns Hopkins, and the Mayo Clinic. I could see being dismissed if I were bringing in blog articles from WebMD or a user content forum, but frankly I’m feeling very disrespected, condescended to, belittled, and I’m rather sick of blatantly being called a liar when I report what I’ve been eating.

    I’ve asked around, and for my area this experience is not uncommon at all.

    There’s no doubt in my mind I have metabolic syndrome, and I need to do something. Any advice on how to get my doctor to consider trying an LCHF diet would be greatly appreciated, especially since what she’s been recommending seems to be actively making it worse.

    • Thanks for the post Wendi. It’s interesting to read. In fact I don’t think this is an uncommon situation. Hopefully it is a question about time. Many doctors are very stuck with the “prudent” low fat diet. That’s what we learned in medical school and it’s generally accepted by the medical community. But we may have a different situation than 30 years ago. So many people are dealing with overweight issues and metabolic syndrome is becoming more and more common. There is abundant evidence suggesting that carbohydrate restriction is beneficial in these situations.

      It is likely that carbohydrate restriction will be more and more incorporated into clinical guidelines for treatment of obesity, metabolic syndrome and type 2 diabetes in the next few years. We see it already being accepted by the scientific community in some countries, like for example Sweden.

    • Ditch the doctor – he sounds like he’s passed his useby date and basing his decisions on dogma rathe than science.

  4. I’ve been LCHF Ketogenic for 1 year I’m at my natural weight, but had to face the doc today re-chol, fasting glucose 4.8 good, HDL 1.09 good, trig 1.75 ok LDL 8.91 shock horror, total cholesterol 10.8 shock horror. Trying to discuss pattern A and pattern B LDL particles cut no ice! Got to face a surgeon soon, what the hell am I gonna say LOL In the UK LDL is indirect ie Freidewald Equation Drs do not want to discuss LDL-Particles

    • Doug.

      These numbers are not uncommon on a ketogenic diet. Some people respond with a very high LDL-cholesterol and high total cholesterol. However, we don’t know what this means in terms of risk. Although LDL-cholesterol is generally associated with increased risk of cardiovascular disease, we don’t know what it means in this particular metabolic situation.

      Your LDL particle number is most probably too high as well, although we really can’t tell much about particle size in your situation. However, a TG/HDL-C ratio less than 2 is to your benefit. If you want to lower your LDL-cholesterol you will probably have to lower your saturated fat consumption, and then replace them by other type of fats, that is if you want to continue with a ketogenic diet.

  5. Dr. Sigurdsson,

    After three months of a low-carb diet my triglycerides went from 186 to 121, HDL from 42 to 48, and LDL from 150 to 199. Is this high LDL level cause for concern?


    • Steve
      This is a typical lipid response to a low carb high fat diet. TG going town and HDL going up is clearly positive. Normally a slight elevation of LDL-C is not a cause for concern. I would suggest you check your lipids on 3-6 months. If there is further elevation of LDL-C you might try to reduce the relative contribution of saturated fat in your diet and use other fats instead, olive oil instead of butter etc.

  6. “The fact that I may recommend a Paleo or an Atkins type diet for some people, does not mean that I am against whole grain or potatoes. Although I recommend everybody to avoid simple refined sugars and junk food, I think complex carbohydrates, starches and not least fibre can be a part of a healthy diet for most people.”

    I admit I don’t understand the notion that “refined” carbs are bad but something like whole wheat isn’t lumped in with the refined carbs group. There isn’t much difference between white flour and whole grain flour – both elevate your blood sugar higher and longer than table sugar does, both are high in phytic acid and lectins, both are loaded with strange proteins humans are adapted to metabolize and whole wheat also has the added detriment of scouring the inside of your intestines due to the insoluble fiber. Yet somehow whole grains get a pass while white flour is demonized.

    And lets not kid ourselves, potatoes are crap too. They’re rapidly absorbed causing a huge blood sugar spike – just because they aren’t processed doesn’t mean they’re good for us.

  7. Thomas DeLauer explains the Science behind Low-Carb Diets and shares the side effects of a Low-Carb Diet so that you can make an informed choice when it comes to your own health. 


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