Dear Dr. Roach: Does obesity have an inevitable result, as in the case of ALS and dementia, or is it a condition that an individual can improve or actually fully control? Are obese individuals predisposed to obesity, and therefore really unable to control their weight?
C.O.
Obesity is defined as having a body mass index — a measure of weight (in kilograms) over height (in metres) squared — of greater than 30. This is an imperfect measurement, since there are very muscular people or truly “big-boned” people whose BMI is high but who have very little body fat.
Waist size is a good measurement of body fat, and the combination of waist size and BMI provides more information about risk of chronic diseases with obesity.
The list of diseases caused or worsened by obesity is long, but especially includes diabetes and osteoarthritis. Heart-disease risk is increased by obesity, partly through blood pressure and cholesterol effects.
If you mean to ask whether obesity inevitably leads to heart disease, diabetes or arthritis, for example, the answer is no. It increases risk of these conditions, but the risk can be managed with a good diet and with exercise. This is important, because the diet and exercise themselves make you healthier. It’s not just a means to reducing weight; losing weight can be healthy, but just having a healthy diet and exercise will reduce risk of heart disease and diabetes, even if you don’t lose weight.
How well people are able to control obesity is a difficult question, but it is certainly not the case that losing weight is easy or simply a matter of willpower. There are many forces that act on eating behaviours, and attributing obesity to mere poor self-control is a disservice.
Medications and many medical conditions are the cause of obesity in some people. The bacteria that live in our gut have some impact on obesity. The people in our social network have an impact.
What is clear is that there are effective treatments. Dietary considerations, exercise and psycho-social interventions all can be effective in helping people lose weight, but the treatment needs to be individualized. Weight management is becoming its own specialty in medicine.
Dear Dr. Roach: Recently, if I stay in bed for a while, my legs below the knee get numb and my toes get a tingling sensation. During the day, when I am walking, the sensation is gone. What could be the problem (and recommendation)?
D.B.
The sensation of numbness and tingling comes from damage to nerves, although many people I see are concerned about circulation issues. The list of possible causes is immense, but the fact that it happens while in bed and not while active suggests that the position you are in is causing compression of the nerve(s). For it to happen on both sides, it needs to be simultaneously affecting two nerves (which would be unlikely for compression) or at the level of the spinal cord or higher.
I can tell you to walk more and avoid bed positions that seem to worsen the symptoms; but I have seen a few people with significant neurological conditions (such as vitamin B-12 deficiency) with symptoms like these, so I think a visit to your doctor or a neurologist for a careful exam is prudent.
Dr. Roach writes: I received some good information about my column on improving patient-physician communication. One piece of advice I received, and one that I often recommend to patients, is to make a list of questions you want to ask your doctor. Another is to bring someone with you. Doctors can help by providing written advice as well as verbal advice. This isn’t always necessary or possible, but it can really improve the patient’s understanding in many instances.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Email questions to [email protected]
