Dear Doctor: My family has a history of diabetes, and although I'm currently healthy (I exercise regularly and am careful about what I eat), I'm still curious about my blood sugar. Do you think it could be helpful to track it as a diabetic would, just so that I know how I'm doing?

Dear Reader: You've asked an interesting question about a growing practice among some non-diabetics. Diabetes is a group of diseases in which hyperglycemia -- that's elevated blood sugar -- results from disruptions to the body's insulin metabolism. Produced by the pancreas, insulin is the hormone that regulates blood glucose concentrations. People with diabetes either don't produce any or enough insulin, or can't properly use the insulin their bodies do produce. The cause of abnormal insulin metabolism determines which type of diabetes someone has.

This inability to manage blood glucose leads to levels that are abnormally high or low, each of which is dangerous. Low blood sugar can cause a rapid heartbeat, dizziness and heart palpitations. When severe, it can lead to seizures, unconsciousness and even death. When blood sugar levels are chronically high, there is risk of long-term damage to blood vessels, heart, kidneys, eyes and feet.

Managing blood sugar fluctuations is the goal of diabetes treatments. Depending on the type of diabetes that an individual has, this is achieved with diet alone, or through diet and insulin replacement. People are considered to have diabetes when a random blood sugar test measures above 200 mg/dL, or when they have a fasting blood sugar level of over 125 mg/dL. A fasting blood sugar level from 100 to 125 mg/dL is considered to be pre-diabetes.

All of which brings us back to your question. Regular blood sugar checks are crucial for people living with diabetes. Those with Type 1 diabetes use insulin and may need to test anywhere from four to 10 times daily. Type 2 diabetes can require two to three checks per day. And while we understand the impulse behind a non-diabetic wishing to track blood sugar, we don't see a clear benefit. The argument in favor is that, with routine monitoring, you'll learn how your body responds to specific foods, which may motivate you to make better dietary choices. Over time, however, the data will confirm what you already know. That is, complex carbs and foods high in protein don't cause the same spikes in blood sugar that you get from refined carbs.

The truth is that glucometers and testing supplies can be costly. A single test strip costs $1. Without a diabetes diagnosis, these are unlikely to be covered by insurance. The same goes for the new continuous glucose monitoring systems, which work via subcutaneous probes that test interstitial fluids. In our practices, diabetic patients already have a challenging time dealing with insurance coverage. We doubt whether insurance would cover the expense for a non-diabetic.

Instead, we think it would be wisest to continue on your current course, with exercise, good dietary habits and regular screenings with your family doctor. Be sure he or she knows about your family history of diabetes, as well as your concerns about developing the disease.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I'm not thin by any means, but I'm not obese either. I lift weights three to four times a week, run about 10 miles a week, play soccer and regularly do half-marathons. Now a new study says that because my BMI is 26, there's no way I can be fit and healthy. Is this true?

Dear Reader: Due in part to the limitations of BMI as a measurement, many athletes and muscular individuals will fall into the overweight category, which is a body mass index in the range of 25 to 30. The body mass index, a measure of body fat based on the ratio between an individual's height and weight, can be a useful tool. However, it doesn't leave room for additional factors like bone density, muscle mass, overall body composition, or the natural variations inherent in the sex, age or ethnicity of an individual.

For example, the BMI of someone who is athletic can skew higher because of the presence of additional muscle, which is denser than fat. Elderly adults tend to have more body fat than younger adults and may have experienced bone loss as well. And on average, women tend to have a higher percentage of body fat than do men.

With athletic individuals, whose habits when it comes to healthful diet and regular exercise are usually quite good, we tend not to worry that much about their actual weight. In these specific cases, we agree that it is possible to fall into the category of being overweight but still be fit.

However, when a patient edges into the upper regions of the BMI category of overweight, or when they register as obese, which is a body mass index of 30 and above, it becomes a different story. At that point we will definitely explain to them the not-insignificant health risks associated with obesity, no matter how physically active the individual may be. These include high blood pressure, heart disease, stroke, kidney disease, Type 2 diabetes, fatty liver disease, metabolic syndrome and certain cancers.

In a large-scale study published last year in the Journal of the American College of Cardiology, researchers from England found that, even when they were otherwise clinically healthy -- that is, their blood pressure, blood sugar and blood lipid levels were all within the normal range -- individuals who were obese were at measurably higher risk of the adverse health outcomes we mentioned above. Even being overweight raised the risk of coronary heart disease up to 30 percent, despite good blood pressure, blood sugar and blood lipid numbers, according to the study results.

The researchers' conclusions came from analysis of data drawn from the electronic medical records of 3.5 million people between 1995 and 2015. However, critics of the study point out that important factors associated with lifestyle, such as exercise habits, diet or stress, each of which can affect or even skew results, were not given equal weight. (Sorry, but we can't pass up an easy pun.)

If the extra pounds that tipped your BMI into the overweight category can be attributed to additional muscle mass because of your athletic endeavors, and if your metabolic markers are all in good order, then in our opinion, you can consider yourself to be fit.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I want to lose 15 pounds but have had no luck cutting calories or carbs, or even trying that crazy (IMHO) keto diet where you eat mostly fat. What about that new diet where you only eat during certain hours? How does it work?

Dear Reader: We think you're referring to time-restricted eating, which is also called "early time-restricted feeding" or "intermittent fasting." No matter the language, these approaches all boil down to the same basic concept. That is, all of your calorie intake, including meals, snacks and beverages, takes place within a limited period of time. Instead of reducing the calories you take in each day, or limiting the types of food you eat, it's the timeframe in which calories are consumed that is strictly defined.

Before we go any further, we'd like to point out that this isn't a weight-loss regimen per se. Initial studies looked into the potential health benefits of the practice, such as blood sugar control. However, in studies done, as well as in anecdotal evidence from everyday participants, it has emerged that weight loss often takes place.

Restricted eating is based on a growing body of evidence that humans do best when we live in sync with our circadian rhythms, which are guided by the built-in "body clock" that operates within us on a 24-hour cycle. We already know that circadian rhythms influence a number of behavioral and physiological processes. These range from the obvious, such as our sleep/wake cycles, to the unseen, like body temperature, hormone secretion, enzyme function and even the speed at which wounds will heal.

So it's not that surprising to discover that nutritional intake would also have a spot on the list. There's no doubt that we've come a long way from the days of our primitive ancestors, when the rigors of hunting, gathering and preparing food, to say nothing of the challenges of storage, strictly limited mealtimes. These days, however, the average American eats from early morning until well into the night.

One of the thoughts behind restricted eating is that, over time, this type of behavior wreaks havoc on our circadian cycles, which use hormones and enzymes to prep the body in myriad ways for nutritional intake in the morning and afternoon. Then, during the subsequent fast, these processes rest. By front-loading our food consumption, as our ancestors presumably did, we allow our inner clocks to sync up for optimal operation. In a study in which men with pre-diabetes limited caloric intake to a six-hour period for five weeks, researchers saw a drop in participants' blood pressure and lower insulin levels.

There's no single formula for restrictive eating. Some plans suggest an eight-hour window for eating, while others stretch that to 10 hours. The one constant is that during the fasting period, nothing caloric -- and this includes the milk in your morning coffee or that handful of nuts at night -- passes your lips. It also appears that reversing the size of meals -- large breakfast, moderate lunch, light dinner -- helps with hunger management. If you do decide to move forward with a restricted eating plan, please check in with your primary care physician for advice and guidance.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)