A perfect height-to-weight ratio varies from person to person and across lifespan.

Noted Medical News Today: "One person's ideal body weight may be completely different from another's. If you compare yourself to family and friends you risk either aiming too high if you are surrounded by obese or overweight people, or too low if everyone around you works as fashion models. Even comparing yourself with people outside your immediate surroundings may not work."

The health website suggested looking at many factors when tabulating a good weight, including age, height, sex, bone density and muscle-to-fat ratios.

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The medical standard is called Body Mass Index. It is one way doctors determine proper weight for maximum health. There are many BMI calculators online including one from the federal government's National Institutes of Health website. A Body Mass Index calculates weight in relation to height.

Medical professionals caution that making a comparison with body weight from person to person is a bad idea. Such comparisons are rarely accurate.

However, researchers noted that in the United States, obesity levels far outpace other nations around the world, making a global standard for body mass nearly impossible, Medical News Today said.

The website added: "Researchers found that overweight people have a lower all-cause mortality risk compared to those of normal weight."

Those with a BMI between 18.5 and 25 are considered in the ideal range. Those with a BMI between 25 and 30 are overweight. Over 30 BMI numbers are considered obese, WebMD said.

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Some medical professionals also calculate waist-to-hip ratios to determine obesity or fitness. They also caution, however, that someone could have a BMI in the normal range for height and weight, "but your health may still be at risk if you are not getting regular physical activity and practicing healthy eating."

Added WebMD: "It's important to remember that your BMI is only one measure of your health. A person who is not at a ‘normal’ weight according to BMI charts may be healthy if he or she has healthy eating habits and exercises regularly. People who are thin but don't exercise or eat nutritious foods aren't necessarily healthy just because they are thin."

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