My daughter (15) is slightly overweight. To reduce weight, she has started following the keto diet. I am afraid that following this diet will have adverse effects. Please advise. — Shalini Gowda, Bangalore Adolescence is a period of constant growth and hormonal changes. It is critical that children in this age group eat a healthy, balanced diet. Obese children should take care to eliminate processed foods and refined sugar from their diets. They also need to exercise and engage in physical activities such as cycling, swimming, jogging, aerobics, and yoga. Any weight-loss diet including the keto prescription should not be started without the advice of a doctor and guidance of a dietician. The fats-intensive keto diet is not balanced, and lacks important nutrients. There are many such fad diets in the market and teenagers should be counseled to avoid following them blindly without professional advice. My 14-year-old son has black spots on his legs. I assumed they are a reaction to him playing sports and games in the sun. But these black spots are spreading towards his thighs. Should I consult a doctor? — Vineeta Vishnu, Kochi There are many causes of black spots on the body. A thorough knowledge of your son’s dietary habits and lifestyle is required to make a correct diagnosis. I suggest that you carefully note down any changes in his food intake, and other activities, such as exposure to different chemicals, weather conditions, and skin care products, etc. This way, you’ll be better prepared to brief a dermatologist who will diagnose the ailment. My nine-year-old daughter’s milk teeth haven’t yet all fallen and one incisor is also yet to erupt. Should I consult a dentist? — Pamela Das, Kolkata Usually in healthy children, incisor teeth erupt by nine years of age in secondary dentition. In some children, this process can be delayed by a year. You should wait for few more months more for normal eruption. If it still doesn’t happen, you should consult a dentist. Also an annual dental check-up is highly recommended. My 17-year-old daughter sleeps after 11:45 p.m every night after her studies. She wakes up again at 4 a.m and does not sleep during the day. I am worried that she is not getting enough sleep but don’t know how to make her reduce her study time. What is the recommended sleep duration for teenagers? — Rima Choudhry, Pune During adolescence, the biological sleep cycle shifts to later sleep onset and later awakening. However, it’s important adolescents get 8-10 hours of sleep every night. As your daughter is managing only around four and half hours of sleep per night, it is definitely inadequate. Help her to rearrange her study time schedule so that she can fit in the minimum sleeping hours. Otherwise she could experience chronic fatigue and her immunity level will go down. This will also lead to poor academic performance as well as behavioural and health problems. (Dr. Soja Vijayan is assistant professor of paediatrics at the Malabar Medical…