Why restoration starts slowly
Restoring weight in someone who is significantly underweight, particularly after prolonged undereating, is a clinical situation rather than a simple bulk. The body has down-regulated to conserve energy, and reintroducing calories too quickly can trigger refeeding syndrome, a dangerous shift in fluids and electrolytes such as phosphate, potassium, and magnesium as cells rapidly take up nutrients.
For this reason supervised refeeding usually begins with a cautious calorie level that is increased gradually while electrolytes and fluid status are monitored. The gut also needs time to readapt, so portion size and food choices are eased in to limit bloating, cramping, and discomfort.
Goals beyond the number on the scale
Beyond reaching a healthier body mass, restoration aims to rebuild lean tissue, bone density, and normal hormonal and immune function, which lag behind raw weight gain. Adequate protein and a varied diet support this, but the pace is deliberately patient.
This is a medically sensitive process. The information here is general education only and is not a treatment plan. Refeeding of a clinically underweight or eating-disordered individual should be carried out under the supervision of qualified medical professionals.