Obesity and overweight in the United States have been on the rise for many years. Remember, this is measured using BMI, which is a population measure. Be cautious when interpreting this number in your personal life. It is not always an accurate indicator of your body composition or your health.
What are some reasons that people in the US have become more obese? What has changed in the past 20+ years? What are some individual and societal factors contributing to these trends?
The medical community defines obesity as a Body Mass Index (BMI) of 30 or greater, while overweight is defined as a BMI of 25 to 29.9. Larger bodies have become more common in the United States in the last few decades. In population studies, obesity is a risk factor for heart disease, some types of cancer, osteoarthritis, sleep apnea and several other health conditions. Overweight when present with other factors like high cholesterol, high blood pressure, family history, or cigarette smoking, is also considered to be a risk. It’s important to note limitations of BMI when it comes to individual risk assessment – this is a measurement created for population studies and people should use caution when interpreting this measurement.
Learn more about obesity by watching Part 1 of the documentary Weight of the Nation. All parts are available for free on Youtube.
BMI is one of measures of body composition, previously defined here. Body composition is defined as the relative proportion of fat mass to lean mass in the body. It is usually measured by percent body fat, but that can be hard to do day to day. So one approximate measure is BMI, which is a ratio of mass to height. This number does not truly give someone an indication of their fat percent and some groups of people tend to have under- or over-estimates of their body composition when using BMI (athletic people, older adults, people who are below a certain height and so on). You can calculate your BMI here – https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm. Another measure is waist circumference, because abdominal fat puts you at higher risk for health complications.
There are more accurate measures of body composition. Calipers can be used by fitness professionals to do a skin-fold measurement to determine body fat percentage with more precision. There are also scales and handheld tools that use bioelectrical impedence to estimate a percent body fat. Less accessible are things like full body tools like air pods, hydrostatic weighing (under water), or special X-rays.
Become more active in your life. You can start slowly, by walking more places or getting off the bus or subway one stop early. Increase activity levels, including strength training and flexibility, until you meet the recommended activity levels.
It is important to prevent injuries when you exercise. There are traumatic injuries that can happen suddenly and overuse injuries that happen from repetitive motions. As a first line of treatment for overuse injuries, you can try RICE – rest, ice, compression and elevation. However, it is important that you see a healthcare professional as well, to make sure nothing serious is going on.
Wear a helmet or other protective gear when riding a bike, skateboard, roller blades and other activities that can result in injuries. Wear the safety clip attached to treadmills – they will stop the machine if you get too far from the safety bar.
Make sure to drink enough water before, during, and after exercise. You probably don’t need to increase your protein intake unless you decide to become a body builder. However, eating or drinking a small amount of protein-rich foods can be helpful with muscle recovery. Make sure you are eating enough carbohydrates for energy.
If you decide to use dietary supplements to enhance performance, first read this https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/. Know that dietary supplements may not always work as you expect, so consider carefully. Using medications like anabolic steroids or human growth hormone to enhance performance is unwise and may lead to health problems.
If you haven’t done much exercising before, or if you’re getting back into it, there are a few things that can help you to plan an exercise program for yourself.
First, make sure to warm up! There are many benefits to warming up – it is a way to slowly increase your body temperature, limber up your muscles and joints, and heart rate. You can do some dynamic stretching or light aerobic activity.
Then, use the FITT principle to focus on either aerobic or strength training, or both. F for frequency – how many times per week will you do it, I for intensity – how hard you need to work, T for time – how long will you do it at one time, and T for type – what kind of activity will you do.
For aerobic or cardio activities, use the guidelines to plan for 150 minutes of moderate or 75 minutes of vigorous activity per week. That can be 5 times of 30 minutes each, or something else that works for you. Intensity can be measured by your heart rate, your breathing rate or METs (Metabolic Equivalents – read more here https://sites.google.com/site/compendiumofphysicalactivities/home). Some examples are here.
For strength training or resistance training, try to exercise all major muscle groups at least twice a week. Try to give your muscles a rest of 24-48 hours between bouts of exercise. Intensity can be measured by the amount of weight you are pushing against. Overload your muscles to the point where it would be hard to do more repetitions. Time is measured not with minutes but with repetitions and sets – a common thing is to repeat the movement 10-15 times, for 2-3 sets, with a rest break of 30 seconds or a minute. Read more here.
Don’t forget to cool down! Now is a good time to do some static stretching of your muscles, especially ones you used during your main exercise. Flexibility exercises can be done every day, but at minimum you should do them 2-3 times per week. Make sure you do not feel pain when stretching, feel the point of tension and stop there – this is the intensity of flexibility exercises.
Can you complete all of your activities of daily life without too much exertion and fatigue? Then you may be physically fit!
We know that exercise and physical activity is important for health. But what kind of physical activity should you do? There are several types of exercise that help with the main components of physical fitness. They are endurance (or aerobic), muscle strengthening, flexibility, and balance. https://medlineplus.gov/exerciseandphysicalfitness.html
Endurance or aerobic exercise helps with cardiorespiratory fitness – this refers to how efficiently your heart pumps blood, how much oxygen your lungs take in, and how well your blood vessels transport oxygen and nutrients to body parts that need them. http://www.shapesense.com/fitness-exercise/articles/cardiorespiratory-fitness.shtml What are some examples of aerobic exercise? Comment below.
Stretching, yoga and tai chi can help with flexibility – the ability of joints to reach their full range of motion. Read about the importance of stretching here – https://familydoctor.org/the-importance-of-stretching/?adfree=true. Some of these activities can also help with balance – this is very important for older adults.
Body composition is another component of physical fitness – read more about it in the post Weight Management. This refers to the relative proportion of fat and lean mass in the body.
Many people in the United States are not getting the recommended amount of physical activity. Studies show that even small amounts of physical activity can increase people’s health. So why is it so hard to move more?
There are individual reasons and barriers to getting more exercise or physical activity. Schedules tend to be busy, people may not know how to exercise correctly and be intimidated, or your motivation may slack when there are other things to do. What other barriers stand in your way?
There are also structural reasons why exercising may not easy for people – no gyms or affordable places to exercise in the neighborhood, poor infrastructure with no parks or playgrounds, no bike lanes, and other environmental factors can impact our ability to exercise. Read more here – https://newsinhealth.nih.gov/2015/05/opportunities-abound-moving-around.
One way we can overcome our obstacles is by first understanding what they are, and then thinking of ways to overcome them. Comment below with ideas of how to increase your physical activity throughout the day that are realistic to your situation.
One of the major risk factors for health-problems like cardiovascular illness is a sedentary lifestyle. Any body movement is called physical activity, things like walking your dog, walking to work, cleaning your house, and so on. More physical activity is always better – https://www.cdc.gov/physicalactivity/basics/index.htm.
Exercise refers to a specific type of physical activity, one that is repetitive, structured, planned, and usually done for the purpose of improving health, increasing physical fitness, or looking and feeling better.
What is BMI? How is it defined? How is it used? The BMI does not really measure percent fat, which is body composition. What would be a better way for doctors to measure their patients’ health?
Describe the Bogalusa Heart Study. What did the Bogalusa Heart Study show?
What health issues and diseases that are related to obesity did the movie discuss?
What are the different influences/risk factors on rates of obesity?
The movie shows several cities in the US, and the maps of different neighborhoods and their rates of obesity and diabetes. Why do different neighborhoods have different rates of obesity?
Why is it important that more children are becoming overweight and obese?
Define ideal cardiovascular health. (7 factors) What are some health behaviors that can help people reach ideal cardiovascular health?
What is fatty liver disease? Why is it dangerous? How can it be prevented?