When you're furiously hitting the gym and counting every calorie, you're looking for movement on the scale and a healthier body mass index (BMI). But in your bid to whittle away pounds and get healthy, don't forget that there are issues on the other end of the scale -- a too-low BMI instead. Your height has a specific healthy range of weight attached to it to help you score optimum health. No, a too-high BMI isn't great, but neither is going under your optimum weight range either. Find your happy place by getting in the 18.5 to 24.9 BMI range and staying put.
Bone and Joint Health
You might have a hard time hitting the gym if your sessions are plagued with pain, but that's the price you pay with a low BMI. When your BMI dips below 18.5, you're at risk for certain bone health disorders, including osteoarthritis and osteoporosis. Brittle bones and joints could stop you from staying on track, so it's worth it to maintain a healthy BMI so you can keep up the good work in the gym and be able to handle day-to-day living activities while you're at it. In fact, a study published in a 2006 issue of the "Journal of Women's Health" found that your risk of low BMI osteoporosis dipped about 12 percent for every point of BMI you gained back into a healthy range.
Being underweight doesn't make you healthier -- in fact, it increases certain problems. Anemia is one of the issues that those with a low BMI may have to face. Anemia is the name for low iron in the blood. Iron is responsible for replenishing red blood cells in the body, but a poor diet and a low BMI can lead to low iron and the issues that come with it: fatigue, irregular heartbeat, dizziness and shortness of breath. That's not exactly great for those who want to live a fit and healthy lifestyle.
A low BMI doesn't just affect you at the gym but also -- ahem -- in the bedroom as well. Women with too-low BMI numbers can expect to see decreased fertility due to reduced periods. When you don't weigh enough, your body immediately goes into survival mode and shuts off all unnecessary processes in order to conserve energy. Your monthly period is one of those processes that isn't required and therefore is lost until you get back to a healthy BMI.
A low BMI indicates that you haven't been fueling your body for the amount of activity you enjoy. Of course, poor nutrition and a low BMI number can lead to a weakened immune system. That means you're more likely to pick up someone else's germs from a treadmill at the gym or catch your child's cold when he brings it home from preschool. You can prep your immune system to fight against germs by getting to a healthier weight, courtesy of a better -- not fattier -- diet.
- Academy of Nutrition and Dietetics: Understanding Body Mass Index
- Time: What’s the Ideal BMI for Longevity?
- Journal of Women's Health; The Association Between Body Mass Index and Osteoporosis in Patients Referred for a Bone Mineral Density Examination; K. Asomaning, et al.
- Canyon Ranch: Why Your Body Mass Index Matters
- NHS: What is the Body Mass Index (BMI)?
Kay Ireland specializes in health, fitness and lifestyle topics. She is a support worker in the neonatal intensive care and antepartum units of her local hospital and recently became a certified group fitness instructor.