Is Cutting Carbs the Key to Losing Weight?

Jodi Helmer
by Jodi Helmer
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Is Cutting Carbs the Key to Losing Weight?

We all know moving the number on the scale requires seriously watching our bread, pasta and pastry intake. A diet too high in carbohydrates — even complex carbs like whole-wheat bread, sweet potatoes and beans — could make it harder to lose weight, according to a recent study.


New research published in BMJ found overweight and obese participants who followed low-carb diets (less than 20% of calories) consumed fewer calories, lost more weight and maintained their weight loss better than those who followed other, higher carb diets.

“Conventional treatment of obesity considers all calories alike. To lose weight, just eat less and move more,” explains Dr. David Ludwig, co-director of the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital and a professor at Harvard Medical School. “The problem is, this advice rarely works over the long term because the body fights back against calorie deprivation. On a typical low-calorie diet, hunger predictably increases and metabolism slows.”

Ludwig wanted to test whether some diets made it easier to lose weight and maintain weight loss. He assigned 164 overweight participants to one of three diets with 20%, 40% or 60% carbohydrates. Those on the lowest carbohydrate diet burned 250 more calories per day than those on the higher carbohydrate diets while eating the same number of calories.

“These findings show that all calories are not alike to the body and that restricting carbohydrates may be a better strategy than restricting calories over the long term,” Ludwig says.


Carbohydrates break down into sugar. Your body needs those sugars as fuel for energy, but consume too many carbs without expending the energy to burn them off, and your blood glucose levels will be chronically elevated, increasing the risk of diabetes and insulin resistance, according to Jessica Cording, MS, a dietitian, health coach and founder of Jessica Cording Nutrition.

Simple carbohydrates such as white bread, pasta, pastries and crackers are especially problematic because they break down quickly, causing sharp spikes in blood sugar and subsequent crashes that leave you feeling weak and cranky. In contrast, complex carbs such as whole-grain bread, sweet potatoes and beans break down more slowly, providing a more sustained energy release.

“It’s very easy to overdo it on carbohydrate portions, especially simple carbs, because they don’t fill us up in quite the same way,” Cording says. “It’s better to pair a complex carbohydrate with protein and fat — like a peanut butter sandwich on whole-grain bread — to help slow the digestive process so you can avoid the sharp sugar spike and crash.”

Ludwig also advocates swapping refined grains and starchy vegetables for slow-digesting carbohydrates like fruits, nuts, legumes and minimally processed grains such as steel cut oats and quinoa.


Changing your diet to include no more than 20% of calories from carbohydrates requires some willpower. (The general population, Ludwig estimates, gets upwards of half of their daily calories from carbs). Unlike the ketogenic diet, which limits carbs to a mere 10% of daily calories, a low-carb diet still provides the flexibility to have some whole fruits, legumes, limited amounts of grain products and even a touch of sugar, according to Ludwig.

If calculating the percentage of calories from carbohydrates feels too overwhelming, Cording offers this advice: Fill 1/2 your plate with non-starchy vegetables, 1/4 of the plate with protein and 1/4 of the plate with complex carbohydrates — and don’t be afraid to make some exceptions.

“The biggest mistake people make when it comes to carbs is trying to avoid them altogether,” she says. “When you feel deprived, your willpower breaks down and you end up bingeing on carbs and feeling awful. Everything in moderation.”

Build healthy habits with the Low Carb Meal Plan. Sign up to receive daily tips and registered dietitian-approved recipes tailored to your personal calorie and carb goals. Go to “Plans” in the MyFitnessPal app to try our 28-day Low Carb Meal Plan.

About the Author

Jodi Helmer
Jodi Helmer

Jodi Helmer writes about health and wellness for publications like WebMD, AARP, Shape, Woman’s Day, Arthritis Today and Costco Connection among others. She often comes up with the best story ideas while hiking with her rescue dogs. You can read Jodi’s work or follow her on Twitter @helmerjodi.


28 responses to “Is Cutting Carbs the Key to Losing Weight?”

  1. Avatar JP Stonestreet says:

    It’s important to note that the research was funded and partially conducted by NUSI, which is Gary Taubes’ low carb research group. Several other studies, even one conducted by NUSI, contradict these findings. I suggest reading Proteinaholic by Dr Garth Davis to better understand how Study methodologies are designed to prove a desired outcome rather than discover the scientific truth. Marion Nestle’s new book Unsavory Truth is also a good read. Diet should be more than a number on a scale. It shouldn’t give you heart disease, cancer or destroy the environment either.

    • Avatar Jamie Carlson-Crump says:

      Thank you for pointing this out.

      And a study of 165 people hardly reflects the overall population. If all of the participants were obese, none are normal diets as control, etc, the data itself sounds cherry picked based on the information provided.

      Honestly if you tell me the study only involved 165 people that is enough reason to throw the data out for me. That is a horribly insufficient sample size. Especially when talking about something as individualized as metabolism.

    • Avatar Rick Yount says:

      How about a study of one — me. For decades, I followed “conventional advice” of eat less – move more, low fat, whole grains, fruits. And I gained weight. Low calorie eating was agony as my body craved calories for fuel but could not burn stored fat AS fuel.

      I hit 277 pounds in 2014, with fasting blood sugar levels in the 160-170 range (diabetic), and was in such pain — joints, chest, and general bloated misery. Blood sugar dropped to 100-110 in a month.

      — Anyone can prove the efficacy of a LC/HF diet for themselves with a simple finger stick blood sugar test. Any foods that cause a large spike in blood sugar should be avoided.

      Test: Take a fasting BG reading. Eat a slice of whote wheat toast. Wait 30 minutes. Re-take the BG test. If you are like me, your BG will have spiked 30-40 points. More than happens with a tsp of refined sugar! That’s the basis of metabolic disease. —
      High and regular blood sugar spikes cause leptin resistance (leptin reduces hunger) and insulin resistance (prevents fat to be burned as fuel).

      Back to my experiment of one–
      I began with Dr. William Davis’ Wheat Belly (high fat, less than 50g carbs, no grains, no refined sugar. moderate protein, pro-biotics) and lost all my carb cravings within a week (after going through “wheat flu” — detoxing from addictive wheat opioids). I lost 95% of my joint pain in 2 weeks and could walk, stand, and stand up without pain. I lost 50 pounds in 6 months when I plateaued in the high 220s. And then began gaining back into the 230s.

      I dropped into ketosis (continuing WB and dropping carbs to less than 20g per day). I later added to that intermittent fasting (but that’s another topic on cell apoptosis and anti-cancer issues).

      The bottom line is this. There are some of us who are highly sensitive to carbs, which — despite USDA nutrition guidelines — are not necessary for overall good health. Just ask Eskimos who live on whale blubber and seal meat. How many slices of whole grain wheat toast do they eat? Yet their blood levels are all normal despite VLC/HF eating.

      McGovern’s Senate Select Committee on Nutrition shot down Robert Adkins’ high fat low carb “Diet Revolution” with their “6-11 servings of grains (half of them whole grains) and low fat” in 1978. The USDA published their Food Pyramid based on these findings in 1979. We have seen exponential growth in cancer, obesity, metabolic disease, t2 diabetes, kidney disease, and dementia since that year. (I’m sure there is no connection to the Wheat Growers’ Association’s strong financial support for the Senator). Present medical practice is to treat the symptoms when these metabolic diseases could be controlled, perhaps eliminated, through rejection of the Standard American Diet (SAD).

      Say what you will about “research” and “studies.” I have proven the efficacy of VLC/HF eating for 4 years now. Anyone who really wants to know the truth for themselves can apply finger stick tests. One week on a VLC/HF diet will (after the misery of wheat flu) prove just how much pain and misery are caused by sugar, breads, pastas, and chips made from wheat, corn, and potatoes.

      That’s my sermon for the week. I’m 70 years old and have my life back thanks to medical doctors and their ground-breaking research of the last fifteen years: William Davis (wheat belly and undoctored), David Perlmutter (grain brain), Jason Fung (obesity code), and Joseph Mercola (fat for fuel). Perhaps medical schools and nutritionists will catch up in the next 10-20 years and begin preventing the diseases they merely treat with drugs today. Or, they may continue to reject the new science and continue to collect remuneration from pharmaceutical companies that make billions treating symptoms.

      • Avatar JP Stonestreet says:

        Does this sound like a troll copy and paste to anyone else? A sample size of 1 is not generalizable. Additionally, there is a lot of false and misleading information in this post. For one, the eskimo lack of heart disease is a myth. Recent autopsies show they all have heart disease, they just don’t live long enough to die from it due to their harsh living conditions. Same goes for the Masai in Africa.

        Complex carbs don’t make you fat and eating a whole-food plant-based diet does not leave you hungry. We eat until we’re full with no need to count calories. It has the added benefit of reducing our risk of heart disease, cancer, diabetes, stroke and a host of other preventable diseases, largely caused by a high fat/high protein diet.

        Diets high in animal products are also the leading cause of environmental destruction. The optimal human diet should not destroy the planet or only be available to affluent people in countries with the means to subsidize meat and dairy so they’re cheaper than healthier, less profitable alternatives.

        • Avatar Thales Nemo says:

          More vegan propaganda!

          Your comment is factually wrong!

        • Avatar jonny87 says:

          What foods we eat are only a part of what’s destroying the environment. How we function as consumers and our insatiable need for new or the latest version of an item more likely has a greater affect on the environment.

      • Avatar Guest001 says:

        Personal, anecdotal experience of one single individual doesn’t compare to normal peer reviewed scientific studies of thousands of people. While your experience is obviously important to you, it has very little bearing in any kind of debate.

        • Avatar Thales Nemo says:

          Your comment is more of the ignored vegan / purdent diet propaganda! The major lie from the purdent/vegan is that CARBOHYDRATES ARE NEEDED AT ALL!

          There is absolutely no need for ANY carbohydrates in the human diet!

        • Avatar jonny87 says:

          Not necessarily true. While it wouldn’t hold up for publication in a research journal, the manner in which this one individual was able to track how adjusting the foods he consumed changed his health status is relevant. In this one instance I would pay a bit more attention to his outcome because he has indicated how he could measure his progress. I’d actually thought of doing something similar because it appears we do have the same endpoint in mind and that is not only weight loss but to change the levels of those indicators of good health.

          Is it overkill probably, in the hands of someone who may be OCD definitely. But I do think many are tired with being bombarded with useless information and want to have a better understanding of how they can change things and know that the changes they’re making are working.

      • Avatar Thales Nemo says:

        Hear,Hear !

        I too have had amazing benefits of going LCHF !

        Bacon and butter rules and makes your pants off!

    • Avatar jonny87 says:

      No, I have no plans to read Marion Nestle’s book because I am well aware that both our government along with industry affects study design, data interpretation, and funding. Conflict of interest is the norm. But I am also not naive enough to think that there is infinite funding to support the unbiased research that’s needed or that incorporates the entire body of unbiased information and provides an honest interpretation of it. It’s just not going to happen soon. That was one of the reasons why I was attracted to Jason Fung’s book and why I’m taking my time going through it. But my BS antenna are still up as I read.

      I’ve learned to ignore the sound byte factoid presented by newscasters who don’t really have a clue or are invested in what info they report. The same goes for most websites such as myfitness pal. That information is typically incomplete or the interpretation is incorrect. But I do go through comments because often I am intrigued by how people interpret the information or I am introduced to new information that I’d like to investigate.

      I prefer to use university studies when I can but even those you do have to review. Google Scholar & Research Gate are pretty good sources of the info I want when I don’t want to pay for the publication but you do have to examine the studies for conflict of interest. Research Gate is good because it tags similar studies that may be related. You can also ask researchers questions or request copies of their articles.

      But I’ve also learned to do what works for me and that means limiting carbs as well as the types of carbs I eat. One diet regimen doesn’t fit all.

    • Avatar Thales Nemo says:

      Your comment has an oder of vegan propaganda !

  2. I’ve lost 40 pounds on low carb so far and feel great. Nothing else ever worked without starving and feeling horrible. I feel great and my tests are great. It’s not going to give me can cancer and heart disease. In fact, the tests have never been better.

  3. Avatar Devin Gray says:

    I think the author seriously misinterpreted the study.

    This sentence – “New research published in BMJ found overweight and obese participants who followed
    low-carb diets (less than 20% of calories) consumed fewer calories, lost more weight and maintained their weight loss better than those who followed other, higher carb diets.” is entirely incorrect.

    The low carb group *did not* lose more weight or do a better job of maintaining their weight. From what I read, all three groups maintained equally well. The researchers adjusted each individual’s calories throughout the study to guarantee maintenance.

    If the low-carb group was burning more calories and eating the same caloric intake, they would have lost more weight. They maintained, so quite simply, they didn’t. Therefore, it’s likely that they ate more calories to maintain. The real question is whether or not they would have done so intuitively if the researchers didn’t adjust the calories of each individual throughout the study. That question can’t be answered by this study.

    “On average, body weight changed by less than 1 kg during the test phase, with no significant difference by diet group in either the intention-to-treat (P=0.43) or per protocol (P=0.19) analysis.” Out of 162 participants, 120 maintained their bodyweight. There were between 53 and 57 participants in each of the 3 groups – high carb, medium carb, or low carb.”

    “Among the randomly assigned participants (for whom energy intake was adjusted as needed to maintain weight loss during the test phase), 120 had data for the primary outcome and remained within the target of 2 kg of their start of trial weight, comprising the per protocol group.”

    Please correct me if I’m wrong. I enjoy the science and appreciate the discussion.

    • Avatar JP Stonestreet says:

      Excellent review of the poor methodology used to prove a claim rather than discover the truth.

      • Avatar Devin Gray says:

        Thanks. That’s not at all what I was saying, though. I didn’t mention any flaws of study design itself, but rather the author’s misinterpreting of the study.

        The methodology of the study is under question, but that’s honestly beyond my understanding as they’re talking about specific methods of measuring caloric burn. There are confounds, as mentioned in the study, such as a higher activity level in the low-carb group before beginning, possibly different levels of brown fat in the starting group, and possible differences in NEAT (fidgeting) in the low-carb group during the study.

        I’m actually quite curious as to why the increased metabolic rate occurred. It honestly doesn’t make much sense and doesn’t fit into what I already know about nutrition. And for the record, I have a BS in Exercise Science, a certification in strength & conditioning, and a certification in nutrition. There would need to be further, more specific studies to determine what mechanism causes the higher metabolic rate.

        Plus, a recent metareview on fat loss concluded that the amount of carb and fat in a diet, as well as the ratio of those two, is irrelevant so long as calories are in a deficit. Calories matter, protein matters significantly in terms of retaining lean body mass and preventing metabolic adaptation, but carb and fat are interchangeable.

        I’m actually a bit stumped as to how they came to their result. If they can repeat the result, and other independent studies can at well, that would be significant. So far, it’s a single study that needs to be corroborated.

        • Avatar JP Stonestreet says:

          Thanks for clarifying. And you’re absolutely right. The author of this article misrepresented the findings of the study. However, the study doesn’t indicate the type of carbs in the test subjects. They could be eating simple refined carbs, and probably are.

          They also didn’t have a group with 80% complex carbs, which is what I eat on the 80-10-10 diet. I’ve lost 30 pounds over 2 years eating this way and my wife has lost 20 pounds. We’re back to our college age weight and my cholesterol is in the “normal” range without statins. I have a genetic predisposition to high cholesterol and took a statin for years.

          These types of confusing and unreliable studies only serve one purpose: create confusion so people can justify a dangerous and environmentally destructive, but profitable diet. These types of studies have nothing to do with discovering scientific truth or helping people get healthy.

          • Avatar jonny87 says:

            No, I don’t think the studies are the main issue. It’s how they are regurgitated in summary and feed to the public. Like the earlier poster indicated there was key information not included in her interpretation.

            We do need to be more concerning and obtain more information on our own instead of believing flawed info or at least question the info given.

            But I think it is also dangerous to look at one singular study. No one study can measure all parameters needed to arrive at how our bodies behave. I also think the objective of the study should be made clear at the outset of this article.

          • Avatar JP Stonestreet says:

            It’s both the study design and the erroneos regurgitation that are the problem. Have you read Marion Nestle’s new book Unsavory Truth? Conscious and subconscious bias is insidious in industry funded research.

            We do need to be more concerned with the totality of unbiased evidence, as you said. However, it’s hard to differentiate the unbiased evidence from the biased because there is SO much biased evidence. Corporations and industry associations churn out hundreds of biased articles, reviews and studies every week. They’re literally flooding us with misleading, false and/or useless information so we get confused and don’t know what to believe. Then we’re more likely to just continue on the path of least resistance.

          • Avatar Devin Gray says:

            The study itself is fine, really. It’s impressive that all 3 groups lost weight equally well, which supports the idea that the ratio of carb to fat doesn’t matter when protein and calories are equal. Especially since protein was equal at 20% in this study.

            I tracked down a PhD researcher who determined that the extra +250kcal in metabolism is because of some tricky math with the statistics. (Kevin Hall, PhD). Which makes sense, because this result didn’t track with anything I’ve read before.

            JP, your individual experience is worth congratulating but is ultimately irrelevant. As are all anecdotes. The bulk of meta-analysis has shown, repeatedly, that the ratio of fat to carb doesn’t matter when:
            1 – calories are controlled and equal
            2 – protein is equal among participants and is at least 20%. Ideally, it’s close to 1g of protein per lb bodyweight. This amount is healthy, too.

            For even better results, add strength training.

            If you’d like to read more to broaden your knowledge, I highly recommend reading the ISSN position stand on diets from 2018. It’s free and is a quick read. It also links each meta-analysis, so you can determine the outcome for yourself.

            They reviewed the most recent meta-analyses and summarized the results. In short – the carbohydrate-obesity model is inaccurate; the ratio of fat to carb doesn’t matter; and while each diet has specific advantages to help adherence, they all perform equally well.

          • Avatar Thales Nemo says:

            Your last paragraph is factually wrong! From Banting through Atkins and the works of Gary Taubes, Nina Teicholz, Dr Tim Noakes, Dr Gary Fettkes and others !


        • Avatar jonny87 says:

          I was a skeptic at first but after reading Jason Fung’s book (The Obesity Code) I think he does a better job of explaining the available studies (both recent & historical).

          I’ve not finished Fung’s book (it’s 300 pages) but most of his interpretation reiterates what I’ve read elsewhere but explains why the body functions as it does in response to different foods.

          I did not read the BMJ paper but this author is not too far off the mark of how our bodies have been interpreted to behave metabolically with different types of diets.

          I suspect she (or others) possibly edited the information to suit the needs of the article or assumed it may be too much for the public to digest. Not the best scenario by any means.

        • Avatar Thales Nemo says:

          Your comment is exactly why dietary advise is ignored, out of date information and debunked calorie hypothesis. A google search clearly supports that it is the intake of carbohydrates which controls weight for the majority of the population!

  4. Avatar jackie says:

    Now I understand why Asians are all so fat! They eat such a high carb diet compared to the Americans!

  5. Avatar Atalanta says:

    From my experience, I do better limiting my carb intake. I’m following WW and have lost 80 so far. When freestyle came out and beans became zero points, my loss stalled. When I went back to the “old way” beans were counted, my loss resumed. I know zero points doesn’t mean free, for me, it just means harder to track.

  6. Avatar Babs says:

    I don’t care so much about the study, I just like the the picture of the dish in this article. Anybody know what it is or where we can find it?

  7. Avatar Kat says:

    What is that delicious dish in the top picture? Is there a recipe for it on the site?

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