DEAR DR. BLONZ: My new partner is about 5 feet, 8 inches tall, but only weighs 115 pounds. I checked his BMI using an online tool, and it is 17.5, which indicates he is underweight. He knows this, but has no motivation to change. Do you have any suggestions? Are there good products to take? For additional information, he is 26 years old and has no health problems. His being underweight is not the result of an eating disorder, and neither of us smokes. -- S.P., Greenville, South Carolina
DEAR S.P.: In western societies, the most common issue associated with body weight is "too much." But there are some, such as your partner, who have difficulty filling out their forms.
You cite his BMI (short for body mass index), which is a measurement that takes weight and height into account. (For an online BMI calculator, go to b.link/naa5r4.) Having a BMI between 18.5 and 24.9 is considered "normal." "Overweight" is when the BMI is between 25 and 29.9, and individuals with a BMI of 30 or greater are considered "obese." The BMI can be considered a reasonable guide overall, but keep in mind that factors such as age, race, sex and body composition are also at play. Heavily muscled individuals may read as "obese" on a BMI chart, for example. An honest self-appraisal in the mirror also works. Based on BMI, a range of ideal body weights for a 5'8" man is approximately 125-164 pounds.
A tendency toward thinness can have several causes. If one or both of his parents are on the slim side, that may be his genetic legacy. There are, however, medical and hormonal reasons for excessive thinness. It is reasonable for your partner to check with his health professional before either of you turn to supplements, diet or exercise as avenues for change.
Assuming that all is OK as you suggest, adding calories should be done in as healthful a way as possible. The primary source of the extra intake should be a mix of complex carbohydrates, healthful fats and protein. Eating more often and snacking with whole foods that have a high caloric density, such as nuts and seeds, will add to the daily caloric intake and provide fiber, a balance of essential fatty acids and beneficial phytochemicals. Rather than eating these foods instead of others, they should be between-meal snacks in your partner's case.
I suggest using food rather than supplements, but there are several concentrated-calorie milkshakes on the market targeted for individuals trying to gain weight. Athletes such as weightlifters, wrestlers and football players often use these weight-gain products to help them gain or maintain weight for their sport. Most of these products contain hundreds of calories; if taken in addition to your regular diet, bodyweight will be gained.
Physical activity should be a part of the process. Resistance exercises and weight training can be helpful. While the thought of calorie-burning exercises may seem counterintuitive when there is an interest in weight gain, the bulking-up experienced with resistance work and lifting (as opposed to aerobic exercise) can add form to the frame.
My final bit of advice: We all need to keep in mind that healthy is as healthy does. This holds irrespective of body weight.
Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.