Nutrition, Growth and Bone Health

Anyone with SMA should have their growth, weight and diet assessed regularly by a dietitian with the aim of working on achieving an appropriate weight, diet and fluid intake. There are no specific growth charts for children with SMA, but a dietitian may refer to standard World Health Organisation (WHO) growth charts. It is recommended a measure of weight and height is recorded at hospital appointments and that Body Mass Index (BMI) is calculated. BMI is a measure that uses height and weight to work out if a person’s weight is within a low, healthy or high range. Anyone with SMA who has a BMI over the 25th percentile should be evaluated for possible obesity and/or excess fat. Body composition should also be measured to make sure the proportion of bone, fat and muscle present in the body is healthy.

Everyone is different but important gastrointestinal (GI) symptoms that medical teams will monitor and treat include: reflux, delayed stomach emptying, vomiting and constipation. People with SMA may also have problems with their ability to break down foods to produce energy (their metabolism). This can result in the blood becoming more acidic – called ‘metabolic acidosis’ or ketoacidosis. They may also have high or low blood sugar and problems with breaking down fat.

The main nutrition-related problems associated with SMA are:

  • Difficulty swallowing
  • Weight management
  • Movement of food through the digestive system