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.

Everyday Inspirations: My Crummy Teeth

“You can’t relate to me because you don’t have a weight problem.” If you are a dietitian working in weight management, you have probably heard this before. If you are a person working with a dietitian, you have probably said this before (at least in your head). I always struggle with the best response to this statement. What am I supposed to say?

  • “No, I can’t relate to you which makes me a terrible dietitian.”
  • “Well, you don’t know anything about my weight history.”
  • “Actually, I also work hard to maintain my weight.”

Don’t worry. I’ve never said any of these things. I just acknowledge the statement and try to move forward in a more productive way.

And then it came to me recently while walking home from a dentist appointment reflecting on my crummy teeth. Let me give you some history. As I child, I had yellow tooth stains from penicillin, buck teeth, and abnormally large gums making for a smile that led to lots of teasing. After bleaching and gum removal, my smile was somewhat improved. Unfortunately, after 2+ years of braces, the stains reemerged accompanied by bright white calcification. In my early 20’s, a mysterious dark stain appeared on my gums above my front teeth. It has never disappeared. And then the cavities…. I have had so many fillings that my teeth weakened leading to my first root canal at age 25. By age 28, I had 3 crowns, one of which has cracked twice in 3 years. Did I mention I grind my teeth?

Every time I visit the dentist, I am complimented on my amazing hygiene. “We can tell you do a great job with brushing and flossing! But… unfortunately there’s another cavity.” It turns out that some people have genetically bad teeth and are prone to these types of issues. Lucky me. For how hard I work at maintaining my teeth (prescription-strength fluoride toothpaste, daily flossing, anti-cavity mouth wash, etc.) and the amount of money I’ve spent on procedures (can we get dental insurance reform?), I deserve a celebrity smile. But it’s not in the genes. Do you see where I’m going with this?

Obesity is a multifactorial disease and one of the factors is genetic. Many people who struggle with their weight have a genetic disposition that makes it easier for them to gain weight and harder to lose weight. How frustrating! It means you can bust you butt exercising and have a near-perfect diet but you still might not reach the weight of a person without this genetic factor. If you want to become a multi-millionaire, join a research lab discovering these genetic components and create a drug or therapy targeting them.

Walking home from that dentist appointment, after learning that my crown had cracked again, I was so discouraged. But then I thought about the state my teeth would be in if I didn’t try so hard. I probably would have had a full set of dentures at age 30. I know I will struggle with my awful mouth for the rest of my life but giving up on hygiene will only make the problems worse.

It’s not fair that you might be prone to obesity. It’s not fair that you will have to work hard the rest of your life to maintain a weight that isn’t your ideal. But what if you gave up? Where would your weight be now? What kinds of health problems would you have? You can’t control your genes (until you develop that drug!) but you can control your response.

And not just the behavioral response such as exercising regularly and eating healthfully, but also your mental response. Maybe you are stuck with some crummy genes in terms of weight but what genes are you grateful for? Is it your eye color, hair texture, skin complexion, or shape of your nose? Is it your ability to sing, play instruments, think analytically, or crunch numbers in your head? Is it your senses of sight, smell, hearing, taste, and touch? Refocus those negative thoughts into something positive before they start impacting your behaviors.

It’s frustrating to have a genetic factor impacting your health but nearly everyone is dealing with one of these challenges in some form. Accept it for what it is, continue your hard work to manage it the best you can, and when you are feeling down, count your blessings. There are always more of those than challenges.

Everyday Inspirations: Make sure your mask is secure...

I have been on quite a few airplane flights recently which means that I have heard the safety speech enough times that I practically have it memorized. While the information is specific to air travel, there’s one line that has stuck out to me as a great reminder for people in the weight loss journey: Make sure your mask is secure before helping others. What happens if you don’t secure your own oxygen mask in an airplane emergency? You may pass out before you are able to help those around you.

And what does this have to do with weight loss?

The majority of my patients are women; they are daughters, wives, and/or mothers and they are givers. (Side note: Of course, men can be givers too! I just happen to see this more often in women). They give of themselves in their families on a daily basis. Additionally, several of them have giving professions such as personal care attendants, health care providers, and teachers. Over the years, they have always put other people’s priorities before their own. They worry about taking care of the needs of others and they neglect their own health needs, such as sleep, nutritious food, exercise, and relaxation. For example, I worked with a patient who took time to make lunches for her three children and her spouse every night but never made her own lunch. Instead, she relied on fast food during the day for herself which was contributing to her weight problem. If you are a giver, I’m sure you can think of similar examples.

It’s wonderful to be a giver but you can’t neglect giving to yourself. To achieve your health goals and live your happiest life, you need to prioritize yourself. If you don’t keep yourself healthy, it is going to impact your ability to give to those around you. Maybe you will be less patient or have less energy due to lack of sleep, or you maybe you won’t physically be able to help someone due to mobility or strength problems, or maybe your life will be shortened due to health problems you have neglected. You need to take care of yourself so you can be the best you, whether it’s as a spouse, parent, child, sibling, coworker, or friend.

In the case of the patient I mentioned earlier, I encouraged her to take a few extra minutes each night to make her own lunch. She did this and started losing weight since she was eating less fast food. Losing the weight gave her more energy and made her feel better about her body, and this made her a happier person and a happier wife and mother. Taking care of herself helped her to better take care of her family.

If you are a giver, tune into whether you might be giving to others at the expense of your own health needs. Remember to make sure your health is secure before helping others. 

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’.