India, Sept. 13 -- My children seem to know almost everything under the sun about health and well-being. At the drop of a hat, they authoritatively spout knowledge about calories, carbohydrates, proteins, probiotics, gut health, intermittent fasting, strength training, glucose spikes, sleep cycles and metabolic fitness. They wear watches that measure their steps, monitor their heart rates, calculate their sleep, and sometimes seem to know more about their bodies than their doctors do.

But a thought often comes to my mind: has this extraordinary consciousness of health necessarily produced healthier habits? The youth health enthusiast today often lives by a curious cycle of penitence and indulgence. There is fasting, followed by feasting;...