Beyond the Scale: Rethinking Ideal Body Weight - Ask a Nutritionist

Transcript:

Leah: Hello everyone and welcome back to our “Ask a Nutritionist” segment of the Dishing Up Nutrition podcast. I'm Leah Kleinschrodt, Registered and Licensed Dietitian, and today we're talking about something that comes up fairly regularly in conversations with my clients, and that topic is ideal body weight. Or in other words, the more direct question I get asked is, what should I weigh?

When I meet with a client who wants to lose weight or weight loss is one of their goals, they'll often come in already having a goal weight in mind. More often than not, it's a weight they were at, usually at a previous benchmark in their life, like when they got married, before they changed jobs, before they started having children, when they hit a particular birthday, et cetera, et cetera.

Then often, specifically clients will then link that previous way to memories of having more energy, just feeling more comfortable in their own skin, maybe feeling lighter and more confident, less stressed, so on and so forth. Who wouldn't want to go back there? In today's show, I want to offer up some thoughts or something to ponder.

And so a couple of questions I'll start off with is what if you could achieve many of, or all of those wonderful feelings, even if the scale doesn't end up exactly matching that same number as before? And what if your ideal weight now isn't necessarily like your lowest or your leanest weight of the past? Would you be okay with that?

How do we determine ideal body weight?

So now we're going to put that line of thought on pause just for a few moments, and let's chat a little bit more about ideal body weight because there are some more formal definitions of ideal body weight. Most of us have seen some kind of chart or calculator, BMI numbers; we'll talk about that in a moment;

Other things that, you know, even been told a specific weight range that we're supposed to, you know, “supposed to be in”. But the truth is the concept of an ideal body weight is much more nuanced than some of those simple numbers suggest. So in this particular episode, we're going to talk about what are those more conventional or medical standards for measuring body weight?

What are the flaws of some of those standards? We're going to talk about why weight alone isn't the best indicator of health. I'm going to pick up where I left off there and just add a different lens in which we can assess our own individual health and an ideal weight range for ourselves.

So in medicine, there's a few common ways that body weight has historically been evaluated. The first and most widely one that I think most people are aware of these days is called Body Mass Index, or BMI. And it's calculated using someone's height and weight. The formula takes your weight in kilograms divided by your height in meters squared. So in the U.S. we use typically more inches and pounds.

So there's some converting to do. But then based on that calculation, we divide up those numbers into different categories. So you're either in the underweight category, normal weight, overweight, and/or obese categories. And then there's actually different classes of obesity according to the BMI.

So the BMI was originally developed back in the 1800s by a Belgian mathematician of all people. Importantly, it was created as a population level statistical tool. So it wasn't meant to be a diagnostic measure for individual health. And so in other words, that means that that BMI was originally designed to find an average, like a, a weight to height ratio average from a large number of people in order to run statistical analyses.

And historically, this was meant to like determine what areas of a population or what segments needed more social resources and things like that. So the BMI was not designed originally to be used on an individual level or on a person to person basis on as a measure of health, but over time, the BMI became widely adopted in medicine because it's, it's free, it's quick, and it's easy to calculate.

Another concept used in clinical settings that is also quick and easy to calculate is there is actually something called ideal body weight or IBW. So these formulas, there's some different ones, but they again, estimate what someone “should” weigh. Again, primarily just based on their height.

I learned something called the Hamwi formula. I'm not sure exactly how you pronounce it, but it calculates ideal body weight by saying that for a woman you start with a hundred pounds for five feet tall, and then for every inch you go up by five pounds.

So you know, if you were a woman who is five foot three, the “ideal” body weight would be 115 pounds. So for men, you start actually at 106 pounds for that first five feet, and then you go up by six pounds for every additional inch over five feet. So equations like these were originally developed for very practical reasons.

Usually it was determining medication doses or specific nutritional needs for hospitalized patients. They were not met to set health or beauty standards. But again, over time these numbers begin to make their way into more of the public domain, and they begin to be used for as benchmarks for what an again, “healthy” body should be.

And that's where we do need to acknowledge some of the limitations and some of the flaws of these more traditional weight standards. So first, neither of these calculations measure body composition. They can't tell the difference between muscle, fat, bone, water. They're just taking that weight and height and saying, basically saying, is your weight appropriate for your height?

So one common example that I think makes the rounds out there is actually like a very highly muscular athlete, like you can say even an Olympian or or a bodybuilder. They will fall into an overweight or maybe even obese BMI category, even though they actually have really excellent metabolic health and they are very lean and they perform very well.

On the flip side, someone with a normal BMI could have very low muscle mass, actually have a lot of abdominal fat, which both of those have their own health risks there. So in other words, body composition is not one thing that actually is measured when we are just looking at the BMI or you’re looking at something like that Hamwi equation.

Second, these equations don't account for differences in body structure, which kind of plays into what I was just saying about body composition. People naturally vary in their bone density, their frame size, their muscle mass, how body fat is distributed. So two people with the exact same height and weight can look very different and have very different health profiles.

Third, the BMI, again, was largely developed using data from European men in the 1800s, which means it's not likely a great representation of today's diverse populations. And research does show that there are various health risks and health risks thresholds that vary based on ethnicity and body composition.

So again, like we're missing a bit of the picture when we're just looking at that BMI. And then with both the BMI and that ideal body weight equation, again, neither of these are also taking into account lifestyle behaviors, which again, like it is difficult to put numbers to those and try to quantify them.

But we do have to recognize that our lifestyle behaviors play a huge role in what our health outcomes are. So someone might weigh more than the BMI guidelines recommend, but they may have excellent cardiovascular health, great blood markers, very balanced nutritional habits, while someone else, who has a normal BMI or might be in that normal range, may have really poor sleep, a lot of stress, poor diet quality.

They might smoke two packs a day. They might have sedentary behaviors that negatively add up and impair and impact their health. So relying solely on body weight oversimplifies a more complex picture. Body weight is just one piece of the puzzle.

And again, dare I offer that it's probably not the most meaningful one, although we tend to, as a society or like as we've been raised, we tend to allocate a lot of meaning onto this one number. So weight doesn't tell us about how good is our blood sugar control? What are our cholesterol levels like? How is our blood pressure? What's our level of inflammation?

Can we physically do everything that we want to be able to do? What is our mental health like? How are we sleeping? Many of these factors that I just listed have stronger links to disease risk than body weight all by itself.

Another reason why weight could be misleading is that the body naturally regulates weight within a range, influenced by genetics, by our hormones, by metabolism and by life stage. So it's natural for weight to fluctuate throughout certain phases of life. And I do hear this a lot from clients.

Usually it's more on the frustration side. You know, I haven't changed what I'm eating. I haven't changed how I'm exercising. My stress is about the same. Yet I've put on a lot of this stubborn weight that I just can't get rid of, or some of my old tricks that I used to use don't work anymore.

And this tends to be the case for a lot of women who are going through those big hormonal shifts of perimenopause and menopause. And I can emphasize with my clients on this and we also really do, we work on weight loss and there are ways to do this safely and sustainably and do it without sacrificing their other health markers in pursuit of some of those extremes of weight loss.

Trying to force the body into a specific number on the scale can sometimes lead to unhealthy behaviors or unhealthy outcomes, so that can look more like extreme dieting, chronic restriction, a big focus shifting into more food and body preoccupation and weight cycling from yo-yo dieting. So weight loss and regain.

That may be, you know, 50, 60. I've had clients that have lost, gained and lost a hundred pounds over and over again. And ironically again, that those cycles of repeatedly gaining and losing weight called what we call weight cycling, actually increases certain health risks.

So this is why I, and I think this is gaining traction that many dietitians and other healthcare providers are shifting toward more of a health centered approach rather than a weight centered approach.

What else should be looked at besides just weight?

So if weight isn't the whole story, what else should we be looking at? In my mind, this is just where my mind goes, but I like to think of this about as like a Venn diagram. So you have all the individual bubbles, like what are all those individual bubbles that eventually intersect at one middle point?

And so what do each of those bubbles contain? Or what, what could we assign to each of those bubbles? Well, one important category is just our metabolic markers from blood tests or evaluations that you get at the doctor's office. So this could be your glucose and your hemoglobin A1C numbers, which that just helps assess our blood sugar control and our diabetes risk;

A detailed lipid panel to measure our triglycerides and our HDL, our different types of LDL, so just kind of our cholesterol panel. We want to look at markers of inflammation like C-reactive protein or CRP. I think it's hugely helpful when clients are able to get a look at some of their nutrition, some of their vitamin and mineral statuses like vitamin D, vitamin B12, ferritin and hemoglobin, which are iron markers.

So all of these can be put in one bucket of metabolic markers that we can look at through lab work. Blood pressure is another one. You know, some people have blood pressure cuffs at home that they can monitor or more often it's just you get your blood pressure taken anytime you go into the doctor's office. So blood pressure is strongly associated with heart disease risk.

And there are different ways to evaluate body composition, which again, just means we're looking at what's the proportion of what our body is made out of. What proportion is muscle, what proportion is fat, what proportion is bone? Just trying to give us a clearer picture of what that body is made up of rather than just looking at the weight alone.

And there's different ways to do this. DEXA scans are one way. So that's not just for osteopenia, osteoporosis. That is one way that we can look at body composition. Many gyms or individual clinics may have something called BIA or bioelectrical impedance analysis.

It's where you stand on little scale and you hold on to the little arms and so, and it's sending low levels of electrical currents throughout the body, trying to, again, get a measure of muscle versus fat versus water. Then skinfold measurements, again, I, I learned those back when I was in undergraduate going for exercise science.

We learned how to take skinfold measurements. I'm not sure how popular those are today, but it still is a method that is out there. And so these methods just give us a clearer understanding of like, where might we put on muscle easier? Where do we, tend to distribute our fat more? What is our percentage of lean mass, which I think are, tend to be a little bit more relevant to health outcomes.

We can look at our waist circumference, which tells us mostly how you know, again, do we have more weight storage or fat storage around our midsection, which more midsection fat versus more in the hips or the butt or the thighs, has a little bit more association with metabolic disease.

And then another bubble that we can look at are actually like what could actually be divided up into a lot of different bubbles are the different various lifestyle factors that are key indicators of health.

So what are we eating and drinking? So our dietary patterns. Another bubble can be what is our physical activity? Are we moving our body on a regular and consistent basis? Sleep can be a whole other entity to itself. Stress management can be another bubble. Our social connection and our social network, our support systems can be another bubble. So these habits often matter far more again than just one number on the scale.

So as dietitians, I know I can speak for the gals who work here at Nutritional Weight & Wellness and other healthcare providers, many of us are working to shift the conversation away from, again, “what should I weigh” to more meaningful questions like how is your energy level? How are your blood sugar levels?

How is your cholesterol level? Are you able to move your body comfortably and regularly? Are your eating habits sustainable and nourishing? We're not yo-yoing in our diet patterns. Are we getting consistent restoration? And that can just mean like restoring through good sleep, but also are you finding ways in your day or in your week or in your month to fill your cup up to instill joy into your life? Joy and pleasure.

So when we focus only on weight, we won the risk of missing the bigger picture of what it means to be a healthy human. But when we look at that overall metabolic health, the lifestyle habits, and our physical function, we can gain a more accurate understanding of wellbeing.

So I think the big takeaways from today's episode are these: there is no one single ideal body weight that defines health for everyone. Weight can provide some information, but it's just one data point among many. The truth is, your ideal body weight may not be the leanest or the lowest weight of your adult life, but it may actually be a weight range that you fall into when those other Venn diagram bubbles intersect and overlap.

So let's not forget to look at metabolic health, body composition, physical fitness, our diet and our lifestyle behaviors when evaluating what the best weight range is for you. Likely that best weight range is the one that is sustainable and enjoyable in the long run.

If you've ever felt frustrated trying to reach a specific weight target, it might help to just reframe and remember that true health is far more complex than a single number. Working with a dietitian or another health professional, we can help look at your overall health and if weight loss is still a goal that you desire or that you think would move you towards that more healthy baseline, let's look at how we can do that in that healthy and sustainable way while also not sacrificing those other metrics.

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So thank you for listening today, and if you found this episode helpful, feel free to share it with someone who might benefit from hearing a more balanced perspective on body weight and health. Have a great day.