I have finally found a diet that works – it consists of eating 17g-20g of protein every meal with unlimited vegetables and salads, and nothing in between for at least five hours. The theory is that this controls fluctuating insulin levels. I also have two or three pieces of fruit a day, and lots of exercise. It certainly works, too. I have lost a stone over the last three or four months, and feel much better about my eating. But is it safe to maintain such a low-carb diet indefinitely?
You want me to be totally frank? Measuring protein content like this for each meal, and to within 17g-20g per portion, is not what eating should be all about. In fact, eating should not be viewed as a "diet", but if this is the way you wish to organise your mealtimes, so be it. It sounds as if what you eat is varied enough to keep you healthy, and that you have finely balanced it against your exercise to keep your weight about right. So if you can keep up your "diet" in this way, you shouldn't come to any harm. But do think about giving yourself a break once in a while and enjoying the pleasure of eating for eating's sake, without constantly counting or calculating.

For the last couple of years, my daughter has had a ganglion, or cyst, on her wrist. It's the size of half a table tennis ball, and our GP has told us it will go away eventually, and that it is stable. Should I be concerned?
A ganglion is a cyst within the "tunnel" in which tendons run from the arm into the hand. It is simply a fluid-filled sac that can be dealt with by minor surgery, or even sometimes simply by aspirating its contents with a wide-bore needle. It may well burst and diminish by itself, but as it has been bothering your daughter for some time, she may think it is now time to take positive action. Ganglions are very common. The old way to treat them was to bang them hard with the family Bible (remember, this was back in the days when Bibles were substantial books and every family had one). Today, you may be relieved to know, we're a bit less brutal in dealing with them.

• Got a medical question for Dr Tom? Email doctordoctor@theguardian.com