Is a Ketogenic Diet a Treatment for Type 2 Diabetes?

I receive questions about the ketogenic diet almost every day that I’m in clinic with patients. While this diet has been around since the 1920s to treat epilepsy in children, it is relatively new in the fields of weight management and diabetes. I recently had the opportunity to speak about a ketogenic diet in the context of bariatric surgery at the ObesityHelp conference. While it works for some people in the short-term, it’s not a sustainable lifestyle for most people to follow for the rest of their life. It also requires the support of trained nutrition professional (like a Registered Dietitian!) to follow it correctly and manage negative side effects. It doesn’t mean that you can’t experiment with it! Just be sure to work with an RD so you can try it safely and effectively.

So what about diabetes? I wrote a blog post about ketogenic diets for people with type 2 diabetes for Fit4D. Click on this link to check it out.

Metabolic Surgery as a Treatment for Type 2 Diabetes

I've been a bit too busy this year to contribute to my blog; however, I did write a post on metabolic surgery as a treatment for type 2 diabetes for Fit4D. I'm incredibly passionate about this topic as it combines my fields of obesity and diabetes management. Unfortunately, despite the number of people who greatly benefit from it, metabolic surgery remains an underused treatment. Through education and advocacy, I'm hoping we can change this trend. Visit the Fit4D blog to read the post.

Exploring the Science: “Fat but Fit” & Metabolic Health

Have you heard of the phrase “fat but fit”? It’s the idea that you can be healthy even with large amounts of extra weight. It is somewhat controversial in medical and public health communities because we don’t want to stigmatize people for having extra weight but we also know that extra weight can carry health risks. In August, a study was published in the European Heart Journal which has added to the controversy. Let’s go through the details.

Who did the research? The research was primarily funded by the European Union Framework, the European Research Council, the UK Medical Research Council, the British Heart Foundation, and the UK National Institute of Health Research. There were nearly 50 researchers from many institutions across Europe including Imperial College London, University of Ioannina, University Medical Center Utrecht, German Cancer Research Center, and University of Cambridge.

Who did they study? The participants were part of the European Prospective Investigation into Cancer and Nutrition cardiovascular disease (EPIC-CVD) case-cohort. A case-cohort is a study where a group of people are identified and followed over a period of time but are not given any intervention. The researchers look at the different things they are exposed to, such as diet choices, work environments, smoking, and alcohol use, to see how it affects their risk of diseases or negative health outcomes.

The EPIC-CVD group included 366,521 women and 153,457 men, mostly aged 35 to 70 years old when they were recruited between 1991 and 1999. They were recruited at 23 centers across 10 European countries: Denmark, France, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden, and the UK.

The participants that were used for this particular study were a sub-group of 17,640 people who were randomly selected from the full EPIC-CVD group and who did not have any history of stroke or heart disease.

What did they study? The researchers followed the sub-group for an average of 12.2 years to see how many people developed heart disease. They wondered what the connection was between body fat, metabolic health, and the development of heart disease.

How did they try to answer their question? The participants completed questionnaires and gave blood samples to have their cholesterol and blood sugar measured. They also had their blood pressure, weight, height, and waist circumference measured.

The researchers used this information to determine how many of the participants were “metabolically unhealthy”. A participant was considered metabolic unhealthy if they had 3 or more of the following criteria at the start of the study:

  • high blood pressure, use of blood pressure medications, or self-reported history
  • high triglycerides or use of lipid-lowering medication like statins
  • low HDL (good) cholesterol
  • high blood sugar, use of diabetes medications, or self-reported history
  • high waist circumference

Obesity was defined as BMI > 30 and normal weight was BMI < 25.

When they looked at results, they used statistical models to make sure that other lifestyle factors weren’t affecting the risk of heart disease. They adjusted for these types of factors: country, gender, age, education, smoking status, alcohol intake, diet and physical activity.

What did they find? They found increased risk of heart disease for two groups of people: people with obesity who were metabolically healthy and people with normal weight who were metabolically unhealthy.

We can think of people who were metabolically healthy and normal weight as our lowest risk group. Compared to this group, people who were metabolically healthy with obesity had a 28% increased risk of heart disease. People who were metabolically unhealthy with normal weight had double the risk of heart disease compared to the lowest risk group.

What does this mean?  Having obesity, even if you are healthy now, means that you are at an increased risk for heart disease compared to someone at a normal weight. There are many people with obesity who will not develop heart disease but it is a risk factor that we must take into account. However, just being at a normal weight doesn’t make you healthy. If you are at a normal weight, you still need to think about the metabolic health criteria: blood pressure, triglycerides, cholesterol, blood sugar, and waist circumference.

When I work with people who are thinking about losing weight, we always talk about what a healthy weight means to them. It’s not realistic or healthy for everyone to be at a normal weight and we can’t pretend that just being at a normal weight will solve everyone’s health and life problems. This study shows us that having poor metabolic health (regardless of weight) is actually more risky than having obesity. On the other hand, we also can’t ignore the impacts on the body from carrying too much extra weight. It’s why I individualize goals to find a healthy and realistic weight range for each person.

Exploring the Science: Long-term Outcomes after "The Biggest Loser"

I’m sure you’ve seen these headlines:

  • “The Biggest Loser”: Their bodies fought to regain weight
  • “The Biggest Loser” contestants gain again: Why weight keeps coming back
  • ‘Biggest Loser’ contestants have slower metabolisms

They certainly caught my attention and I was excited for another opportunity to explore the science. Where are these headlines coming from? On May 2nd, an article titled “Persistent metabolic adaptation 6 years after 'The Biggest Loser' competition” was published on the website of the journal Obesity.

Who did the research? The research was supported by the National Institutes of Health (NIH). Most of the researchers were affiliated with NIH, one was affiliated with the Washington DC Veterans Affairs Medical Center and one with Towson University in Baltimore.

Who did they study? The participants were all competitors on “The Biggest Loser” television show. They had agreed to participate in a study 6 years ago when they were doing a 30-week weight loss challenge on the TV show. Of the original 16 participants, 14 agreed to be in this current study: 8 women and 6 men. When the participants started "The Biggest Loser" competition, they all had obesity. Their average starting weight was 328 pounds and they lost an average of 128 pounds. In this study, 6 years had passed since they finished "The Biggest Loser".

What did they study? The researchers were testing the resting metabolic rate (RMR) of the participants. RMR is the amount of calories that your body needs every day to maintain your current weight without adding any extra calories for exercising. Usually, the higher your body weight is, the higher your RMR is because there is more of you that requires calories or fuel. After losing weight, it is normal for RMR to decrease because there is less of you. But sometimes the RMR goes even lower than we would expect based on your body weight. This is called ‘metabolic adaptation’ and it is believed to be one of the reasons that people regain weight. The researchers were wondering if “The Biggest Loser” participants would continue to have metabolic adaptation 6 years after the competition and if the metabolic adaptation was related to weight regain

How did they try to answer their question? The researchers looked at the weight and the RMR of the participants at the end of the competition and 6 years later.

What did they find? "The Biggest Loser" participants all had lower RMRs after losing weight in the competition. Six years later, 13 of the 14 participants had regained weight; 5 of them had regained almost all of the weight they had lost. The surprising part was that the RMR of 9 of the participants did not increase even though they gained weight. The researchers also found that the subjects who had lost more weight at 6 years after the competition continued to have lower RMRs but this wasn’t surprising. Unfortunately this is one of the challenges faced by people who lose weight. One positive outcome was that 8 of the 14 patients maintained a 10% weight loss over the 6 years. While this is much less than the amount of weight they originally lost in the competition, it is a better success then we would see in most weight loss studies.

What does this mean? We already knew that metabolic adaptation happens after losing weight and it makes it hard for people to maintain their weight loss. Since they need fewer calories to maintain their new weight, they have to be very strict forever and that’s not realistic. We didn’t know that RMR would stay low even for the patients that had regained weight.  This was concerning because it would be even more difficult for those people to lose weight again. This tells us that once we have been carrying large amounts of extra weight, our body wants to settle at that weight and it makes it difficult to maintain lower weights.

There is some research that suggests that people who have bariatric surgery, such as Roux-en-Y gastric bypass, do not have the same level of metabolic adaptation. Their RMR gets lower after losing weight but it doesn’t keep getting lower over time as they continue to lose weight. This might be an advantage of bariatric surgery that helps people to maintain a greater weight loss for longer than we see in non-surgical weight loss. But we’ll save that for another post on ‘Exploring the Science’. 

Exploring the Science: Dairy Fat and Risk of Diabetes

On March 22, 2016 a study was posted online, or “ahead-of-print”, on the website of the scientific journal Circulation. The title of the study is Circulating Biomarkers of Dairy Fat and Risk of Incident Diabetes Mellitus Among US Men and Women in Two Large Prospective Cohorts and it has generated a lot of buzz over the past few weeks. Here are just a few of the headlines I saw:

  • Skim Milk Could Increase Your Risk of Diabetes, Study Suggests
  • The Case Against Low-Fat Milk is Stronger than Ever
  • Are Full-Fat Dairy Foods Better for You After All?

As I mentioned in my introduction post, I plan to use this blog to explore the science behind the headlines so this seemed like a perfect study for this series.

Let’s start with the “publish-ahead-of-print” category. It means that this study has been accepted to be published in the journal Circulation but it hasn’t been published yet. Right now, it is being prepared for publishing which means copyediting, typesetting, proofreading, and author review. Since this process hasn’t been completed yet, the final article that gets published could be different than the article that is currently online in the “publish-ahead-of-print” category. We’ll look forward to seeing the final article once it is published.

Who did the research? It is a group of Boston researchers from well-respected institutions. Most are affiliated with Harvard Medical School, Harvard School of Public Health, and Brigham and Women’s Hospital, and one researcher is affiliated with Tufts University.

Who did they study? Their participants were two large groups of people who have been studied for many years: 1864 women in the Nurses’ Health Study and 1469 men in the Health Professionals Follow-Up Study. These study participants agreed to be studied back in the 1970’s and 80’s. They agreed to answer questions about their health, eating habits, and lifestyle habits over the years so the researchers could learn about how their choices linked with their health.

What did they study? They looked at biomarkers in blood samples that had been taken from the participants in the 1980’s and 1990’s. Biomarker, short for biological marker, is a body factor that can be measured and is linked to a specific body process or disease. In this situation, they looked at biomarkers that would be created in the blood from eating dairy fat. Their research question was: Are people who have higher levels of dairy fat biomarkers less likely to get diabetes?

How did they try to answer their question? They only studied the blood of participants that did not have diabetes when their blood was drawn. Since the participants had agreed to answer questions about their health regularly, they used the participants' reports to see how many of them had diabetes by the end of 2010.

What did they find? They found that participants with higher levels of dairy fat biomarkers in the 1980’s and 1990’s were less likely to get diabetes by the end of 2010. Depending on which one of the three biomarkers they looked at, participants with higher levels had 43-52% lower risk for diabetes than participants with lower levels. Some participants with higher levels of dairy fat biomarkers still got diabetes but it was less likely to happen compared to the participants with lower levels of dairy fat biomarkers.

What does this mean? There is a link between dairy fat biomarkers and the risk of diabetes but this study is showing correlation and not causation. A correlation means that two things are linked but it doesn’t mean that one thing causes the other thing. We can't say that eating dairy fat prevents diabetes because some patients with higher levels of dairy fat still got diabetes. We also can't say that avoiding dairy fat causes diabetes because not all of the patients with lower levels of dairy fat biomarkers got diabetes. We just know that people with higher levels of dairy fat biomarkers have a lower risk of diabetes compared to people with lower levels of dairy fat biomarkers.

For us in the nutrition world, we hope that this study will lead to more research so we can better understand how dairy fat impacts our health. We have been recommending low-fat and fat-free dairy products for many years because they are lower in calories and have less saturated fat than full-fat dairy products. However, some other studies are also suggesting that the saturated fat from dairy products might not be bad for our health. A study like this makes health professionals think critically about what we are recommending and why we recommend it. It's one of the exciting parts of being in the world of nutrition science. We still have so much to learn about nutrition and our bodies and the ever-emerging research keeps us on our toes.