Question:
I'm in my mid-twenties. I'm less than two metres tall and weigh between 75 and 80kg, which puts me near the light end of the BMI. I have real difficulty maintaining that weight. I know a lot of people would kill for my situation but it is a problem for me. I eat really well, I have protein supplements between meals and I am physically active but I can't get above the 80kg mark. And if for some reason I miss a meal or don't eat right, I notice it straight away and lose weight. Could there be an underlying problem with my health that stops me from gaining weight?

Answer:
Everyone's weight will be affected by a variety of factors including the amount of energy eaten daily, exercise levels and metabolism. Some people are also genetically naturally slimmer. I am wondering what sort of weight your parents are or were at your age. As a starting point, if it is hard for you to maintain weight, it's worth getting checked out to make sure there is not an underlying metabolism or other medical issue that is getting in the way of weight gain. Your GP is in the best position to get you started. They will want to take a full history to look at food choices, exercise levels, sleep patterns and there will also be questions about metabolism and hormones — for example, do you suffer from palpitations, a racing heart, increased sweating or anxiety? Sometimes blood tests will also be ordered to check thyroid hormone levels or other markers involved with metabolism. If all of those checks are clear and your lower weight is not linked to other issues, a dietician can help ensure your nutrition is adequate and can suggest ways to boost energy intake. Supplements can be used (many body builders use protein supplements to keep their weight up), but in the long term, whole foods such as nuts, whole grains, dairy, fruit, vegetables and lean proteins may be better and more affordable choices for a healthy weight.