Mend Your Diet

Dangers of a low/underweight BMI?

I've been hearing a lot about BMI recently and there's a lot of information about obesity but none on being underweight. Apparantly a BMI of lower than 20 is underweight. My BMIs 16 so is there any danger in this? I've never dieted and in fact have tried to gain weight in the past but with no success. I eat a very healthy diet... 3 meals a day along with snacks, at least 5 fruit+veg a day, 3 portions of wholegrains a day, nuts, tofu etc. I don't eat healthy to keep my weight down... I just dont want to put many processed foods in my body. I used to eat very unhealthy fatty foods but my weight was the same then as it is now. Admittedly I don't exercise much but other than that I'm generally very healthy. So why do the experts say my BMI is unhealthy? What are the dangers of having a low BMI and what's my fate if I've tried but can't gain weight? Thanks Ghettoca :o) My body fat percentage is 17-18% by the way... is that ok? Thanks for your answer sam but I can assure you that it's not easy putting on weight when you're genetically very skinny. I'm 22 now and throughout my teens I tried to gain weight... I went to a dietician and was eating so much food at one point that I actually felt ill most of the time (and no I'm not bulimic!). For years I just couldnt put on weight even though I really wanted to (it's not only obese kids that get teased about their weight). All that eating wasn't making me put on weight and I was feeling miserable and full all of the time so I gave up. I can assure you I eat a very healthy amount now and am not a fussy eater. I just dont understand why people say it's unhealthy to have such a low BMI when I'm generally very healthy and eat as much as anyone else. I can't understand how I can be 'malnourished' when I eat a normal amount of food.

Public Comments

1. well BMI is a load of bull shit ya c u can b 5'5 200 pounds of pure muscle right and then you have a guy thats 5'5 200 pounds of fat they have the same bmi it says there both overly obese(allthough the fat guy is and needs to loose weight) i dont go by BMI i got by body fat percentage or how i look in the mirror and you dont have anything to worry bout g 17-18 percent of body fat is alright its in the athletic range for women just dont let it fall below those points and ull b fine
2. Hi, first of all, are you sure your BMI is 16? to work it out, its your wight (in kg) divided by the square of your height (in meters). yes, a BMI of 16 is very low, people in that group are diagnosed as mallnourished. my BMI is 23 and i am thin a low BMI is associated with health problems that depend on your age and sex. if you are a teenager, it could have a negative effect on your growth and development, many women if they become severely underweight, they experience aminorhoea or oligomenorhoea (i.e. your period either becomes irregular or stops completely), being malnourished also has a negative impact on your immune responce so you become more vulnerable to common infections there is alot you can do to gain weight. in my opinion, it is much easier to gain than to lose weight but again in depends on what the underlyeing problem is. do you like food? is there a particular type of food that you enjoy? are you a fussey eater? these are things that you can work on. a BMI of 16 is unlikely to be a healthy thing good luck
3. Seem like you've just got really low lean mass, i.e. not much bone/muscle weight. You could try strength training a few times a week combined with a high protein diet to build muscle mass. 17%-18% body fat is usually considered to be in the 'athletic' range for women. But usually these women are not underweight, they are just very muscular so their body fat percentages are low. Perhaps aim to get a BMI of 18 and keep the body fat at 17%-18%. So it would be a combination of gaining mostly muscle, but also a little fat to keep the body fat percentage where it is.