so body composition is next so first off what is body composition this is basically the ratio of fat tissue to lean tissue so another way that we often refer to this is as percent body fat or body fat percent okay so that's in Essence body composition why do we measure it well first off too much or not enough is not ideal for health but also it tends to be a better marker of health status than just weight so we've talked about weight ideal body weight BMI those certainly have their place however body composition can take it a step further and really look to see how much body fat versus body muscle we have so let's talk a little bit about the types of fat on our bodies we have essential this is what just what it sounds like this is the fat we need to have for optimal function examples include fat that's found in the lungs in the intestinal tract in the central nervous system we need it to function women have higher body fat percent for essential than men because we have a reproductive organs so we have breast tissue we have uterine tissue which has more fat associated with it so that's essential what we need for just overall healthy functioning stored fat is also called adipose tissue you've probably heard of that term adapost tissue can be in two forms we can either have it viscerally or subcutaneously so that's what we're going to look at next okay so again essential what we need for basic body functions stored fat or atopos tissue we have in these forms of visceral and subcutaneous so both of these types of adapost tissues are important for us they insulate the body from temperature uh they also can help help cushion our organs protect our organs uh so let's look at them and then we'll get into some of the the health Associated factors so over here on the left you see subcutaneous fat this literally means Under the Skin So This is Under the Skin same for the gentleman on the right he's got a thinner layer of subcutaneous fat visceral fat is found around our organs so this gentleman on the left he's got a little bit more of that going you can see the yellow that are around his organs in between his organs whereas the gentleman on the right he's got it is just not as prevalent not as present okay so that's a definition of this type of fat in terms of health outcomes visceral fat so the fat around our organs between our organs tends to be more associated with negative Health outcomes this type of fat is more active and what that means is this Central type of fat this visceral fat releases hormon hormones and hormones can influence things like insulin levels they can influence inflammation in the body they can also increase LDL the bad cholesterol and a bunch of other things but those are some of the factors we've talked about in our class so insulin LDL inflammation can be increased with or affected with this type of fat as a result visceral fat having a higher amount of it is associated with conditions like diabetes high blood pressure heart disease so on I will say that visceral fat is easier to lose so if someone partakes in weight loss visceral fat is easier to lose because it's more active metabolically so our bodies are more predisposed to want to get rid of it subcutaneous fat is not nearly as active it doesn't release those same hormones as a result though it's harder to lose H so we we can certainly find cases is where folks have more of that going than the visceral so my point here to summarize body fat location does affect health status so where we find it whether it's under our skin or around our organs does influence Health also the distribution around our entire body can play a factor with health so let's take a look at that here men tend to accumulate fat around that belly and the abdomen this is also known as Android or sometimes known as apples shaped obesity that doesn't mean that every man is going to collect body fat here some men collect it more in the lower half of the body but as a whole this is what we see whereas women tend to be more pear-shaped here they tend to accumulate actually more subcutaneous fat than visceral fat again you'll find women who have more Central fat than lower body fat so this isn't going to be black or white one way or the other but as a whole this is how the two s Sexes accumulate fat so looking at the apple shape here this tends to be more visceral fat that's accumulated so we just learned that's more associated with health risks it is easier to lose this is one reason why men lose fat weight faster than women women tends to be more subcutaneous uh it's not as harmful with those metabolic risk however it can be harder to lose so here's just the image of those two types of fat again subcutaneous and visceral so be comfortable with those the last topic related to Fat your textbook had a a nice section on white and brown cells these are fat cells so atopos sites are fat cells most of them on our bodies look like this on the left this is our standard white adapost tissue it's got a lot of fat stored in it and that is really the purpose of our fat cells is to store fat to store energy when we might need it on the right hand side there's a type of fat that's called Brown ose tissue or cells this has more mitochondria and you see those here in the cell itself the function of this type of fat is to generate heat so not so much to store fat it does store a little bit however its General function is to generate heat when we're born we actually have a high high percentage of these Brown atpo sites the reason is to maintain our body temp temperature to keep our our temperature where it needs to be however as we age we lose this type of fat and we then have more standard white atpo cells develop there's some interesting research on this it's more detailed in your book if you're interested in reading on it uh in a nutshell the more Brown atopus tissue we can retain as adults the lower bmis we have so there's some research looking into this how can we maintain Brown atopos cells and not lose them as we're we're for growing up so that's that's all I'll mention there but some interesting stuff with this so we talked about body fat what is a healthy range well you can see here the essential amounts and then desirable they call it fatness for good health I'm going to give you even an easier number to remember Here For Men We generally recommend about 3 to 25% so that's a lower range here upper range here 3 to to 25% for women about 12 to 30% so 12% up to 30% so please do remember those ranges next up how do we measure this okay so we talked about how important it is we know the ranges how the heck can we measure it well there's several techniques I'm going to present just the overview of many of these more complex ones and then we'll get into ones that we can use more first off is underwater weighing so those of you in exercise movement science you'll learn about this a bit more we have this device on our campus uh the bottom line and again I'm keeping this basic for us the bottom line here is this can measure your body volume okay so we weigh you before we dunk you we weigh you on land and then we weigh you underwater so you would Breathe Out all of your oxygen and you would dunk under the water and we would get a weight for you the difference there between your weight on land and your weight underwater is volume so in essence we're calculating your volume that allows us to use some equations that can then calculate your density and then body fat percent uh the equations are actually listed in your textbook so if you're interested in exercise Fizz check them out they're going to walk you through how to determine uh density from volume so again we calculate volume here then we convert it to density and then body fat percent uh in terms of the need to nose here it's about 2 to 3% air so we might say that we get 25% body fat for you it can actually be anywhere from 22% to 28% so still fairly accurate there the negatives of this well it's pretty complex and not very comfortable we don't really uh want to do this for a lot of our individuals it's mainly used for athletes uh I've seen it used in in research settings but it's not the most comfortable as well as if someone had a bit of extra body fat it can be harder to have them submerge under underwater so it has its limitations but you exercise movement science students you'll certainly have some experience with this as you progress in your studies here the other one that looks at volume is air displacement uh plethysmography basically this measurement is going to assess how much air you displace when you're in this canister when you're in this bod pod as we we call it so going back on the previous premise if we can calculate volume of you of your body then we can determine density and body fat percent so again check out your book if you want to get into more of the underlying reasons for this but that's that's it in a nutshell both of these measures will assess your volume which will then help us calculate through a few steps your percent body fat positives of this it's about 3% so similar to underwater weigh it's convenient uh tends to be much shorter it's about 2 minutes uh all you have to do is we swimsuit or spandex the negatives some people don't like to wear swimsuits uh as well as accessibility not always as this accessible to the general public and actually we find that our third measurement that we'll look at tends to uh be even more accurate and more reasonable so we don't really see the bod pod used as much unless we have it for research study of some sort so let's look at the third one here this is dexa this is a measurement that uses an x-ray to detect body fat percent as well as bone ma bone mass excuse me so if you've ever had your bone mineral density checked they're using this device this is what we screen for for osteoporosis so with that the technology also allows us to estimate lean tissue lean body mass and from there we can calculate your 4% body fat uh so what are some positives very accurate it's about 1 to 4% error so quite accurate it's non-invasive no one has to strip down into a swimsuit with this it's about 10 minutes in length and they would just lay on this dexa machine in a relaxed State the negatives the biggie that I find is accessibility so we don't always have access to this we do on campus we actually have one that can measure you but for for the general individual uh they would have to go to their doctor and then be sent to a hospital to get this measured and that that can be very expensive so the accessibility Factor can be a limitation so those three are the more I guess high tech ones if you want to use that term Bia is a little bit lower technology it's not as accurate though we tend to have that lost whenever we go to some of these simpler ways however they're more practical so with bi electrical impedance analysis what we're measuring is the body's resistance to a current so we're going to send a low energy current through the body and then depending on how much fat someone has it will either imped the progress of this current or if they don't have a lot of fat the current can flow quite well you guys have probably heard muscle and water electrolytes those are more open to electrical currents going through them whereas fat tends to impede or block the flow of energy currents so if someone has a lot of body fat on them then this device would measure that there's a lot more impedance whereas if someone has a lot of lean tissue the current is able to flow through much much more efficiently uh so bottom line it gives us a percent body fat so again a lot of calculations involved but for us we just need to know that it estimates body fat percent it's cheap it's fast there are some limitations though it's not as accurate as the others I've seen error rates of up to 10% so say that we measure you and you're this 19.5% that we're finding on the the image on the right you can actually be anywhere from 10 and A2 to 29 and A2 or I'm sorry 9 and a half up to 29 A2 so is that really is that really a good estimation uh you be the judge of that the other negatives it's very strongly affected by hydration so if you're dehydrated it's going to measure you at a higher body fat percent than than not uh one other limitation I'll mention because this is used in a lot of gyms or or uh places like that be careful with some of these handheld devices what research has found is they tend to measure more of the upper body fat because that current when you're holding on to the metal probes here that current isn't going to be strong enough to get all the way down to your feet so if you're female and you carry more weight in the bottom part of your body it may give you a lower reading even though your your overall body fat percent might be higher uh same thing with the scales you guys may have seen those where you step on the scales and they have these probes and they're to estimate your body fat percent that electrical signal isn't likely going to make its way all the way up to your arms and your neck so use those with caution I think they can be used for uh looking at it over time so measuring over time and seeing what it's doing but I wouldn't put all my eggs in one basket with this particular device and then finally we have some simple anthropometric measures that we can use the calipers can be great if someone is trained and knows what they're doing and that's probably the biggest limitation is uh individuals not being trained on how to measure this students who are taking EMS so exercise movement science or dietetics we'll teach you how to use these and the Assumption here is if we can measure your body fat here the subcutaneous fat we can estimate how much total body fat you have uh so positives it's pretty fast and simple it's cheap compared to the other measures the negatives in addition to the measurement error uh if someone is extremely obese it's not ideal to do this because it's going to be difficult to to get that subcutaneous fat into the calipers and then the other thing to keep in mind one measurement like this here this is the Supra iliac body fat or skin fold excuse me sua iliac skinfold you really need to measure several different sites the gold standard is to measure seven sites around the body and then plug them into a calculation I actually have an app on my phone that I use because I I use this measurement and you just plug in those numbers into the calculator and it will do it for you but keep in mind that one measurement like this or the tricep skinfold that's not going to give you a percent body fat you'd have to do a variety of them and then do some math uh the bottom one waist circumference this can be a really quick and easy way to assess someone's risk for health uh the waist circumference measure measures central obesity so a lot of times that visceral obesity and research suggests that it correlates very well with BMI and per body fat so if we're carrying excess weight in our midsection then it tends to be an accurate reflection of our health status so the numbers to remember with this and these are going to be on your exam above 35 in is a health risk for women above 40 in is a health risk for men so we just use a simple tape measure measure in inches above 35 for women and above 40 for men is considered to be at risk for for chronic diseases okay one other thing I wanted to show you I thought this was really cool in your book I'd never seen this before so I didn't include in the slides as I feel like I've covered a lot of information already but just an FYI for you so I'm in uh one of the latter sections of chapter 14 I'm going to scroll down here they talk about BMI and then there's a section that calculates BMI to per body fat so if you can calculate your BMI which you guys know how to do now you can estimate your percent body fat without using a bod pod or a dexa or any of those things there's a formula here for both men and women that you would use and you would just plug in your values so this accounts for age so that's the biggie and then gender so females use this formula males use this formula you get your BMI calculated and then you can do the math to determine your percent body fat so FYI but I thought it was kind of neat to to include just as for you guys here not necessarily something you need to memorize okay so just a little bit more from me here so today we've looked at a lot of numbers right BMI ideal body weight percents uh body fat keep in mind these are helpful adjunct when we're looking at someone's Health but there are so many components to health status and one number or even a group of numbers should never be the end all be all we do need to remember that we want to look at our clients in a holistic way so if you don't remember the abcdes go back to them this is the concept that dietitians use to assess clients so we look at anthropometrics we look at their Labs we look at their diet we look at their lifestyle their exercise levels etc etc and one way that I like to determine or I like to Define excuse me a healthy body weight is a weight that's easy to maintain for someone when they're eating well and they're being active and also a weight that includes solid blood markers so keeping the cholesterol levels low keeping the blood pressure low and that can vary from Individual to individual uh we seem to in our society have an over Reliance on some of these numbers they can be valuable yes but we don't want to lose track of that big picture and the last thing I'll mention here the overreliance on numbers has led to a bit of this skinny fat phenomenon we see our health professionals recommending so much lose weight lose weight lose weight but they're not really talking about things like gain muscle and lose weight have a lower body fat percent and that can lead to an individual feeling like okay I'm at a healthy weight but they may not have the best health outcomes uh there's research that suggests that your health risks are much increased if your body fat percent is high even if you're at a healthy weight so say that you have 130 lb female just looking at her she might look like great she's at a nice weight for her height however if her body fat percent is 40 that that's not a good thing that can really increase the risk of future health problems okay so just factors to keep in mind as you progress many of you will be working with individuals and weighing them and talking about these Concepts so I don't want you to just solely focus on those numbers the final topic of this section I decided to have more in a self-study form I'd like you to read the health connection it's a Well written uh I I went with this because I think the textbook covers the key points I would cover and uh you guys have spent a lot of time listening to me over the semester so I thought you could do this one on your own that said it is important to be aware of disordered eating thoughts and tendencies especially with our younger groups so as you read through that section here are some key questions that I'd like you to be able to answer so kind of mini objectives if you will for this section and uh the book does again a nice job at overviewing these and providing some ideas of treatment options the next slide I thought this was an interesting study and it ties in well with the topics I discussed today particularly how we as a society have such a strong strong emphasis on a number a number on a scale so I'd like you to just read through this as some food for thought the final two slides I wanted to include because College age students you guys many of you guys tend to be higher at risk for disordered eating Tendencies so this was a nice checklist in your book that you can go through and if you answer true to some of these questions then I do want to encourage you to consider seeking assistance uh eating habits as well as body image can be improved and it can have great lasting effects on the rest of your life we have counselors here on campus we have a dietitian those together working with those two uh groups can really help to have someone normalize their eating patterns if someone is not interested in going to that that route they don't want to meet with somebody we have an excellent program called body youu this is something that is a self-guided program so it's free it's Anonymous you do it on your phone or your computer and you go through the modules on your own at the beginning of this if you're interested in taking the the body you program they actually have you do a survey and then they place you into a program so some folks might be better at or might might get more benefit from a program design to help stress levels others might uh do better at a programmed aim for depression others more for disordered eating Tendencies so great program if you're interested uh get get on that website and check it out all right thank you for listening to chapter 14 I hope it's been an interesting chapter for you we'll build upon these Concepts as we progress into chapter 15 which will cover obesity as well as weight management