A large amount of hair loss after weight loss may be resting hair loss. Resting hair loss refers to the normal resting pestle hair caused by a variety of stress factors excessive loss of hair, a large number of hairs at the same time into the resting phase, mainly for the following reasons: 1, excessive stress: hair growth will go through the growth phase, regression and resting phase, when a person feels excessive stress will lead to hair growth to stop and enter the regression and resting phase, excessive attention to weight problems lead to mental tension, easy to Hair loss; 2, iron level is reduced: weight loss process to limit the diet, easy to lead to iron deficiency, iron deficiency will lead to a reduction in blood supply to the hair follicle, or local neuroregulatory dysfunction, resulting in malnutrition of the hair follicle, resulting in hair loss phenomenon; 3, protein and trace element deficiency: the main component of the hair is protein and zinc, iron, copper and other trace elements, dieting and weight loss people protein and Micronutrient intake is insufficient, but also easy to make the hair due to severe malnutrition and loss; 4, drug side effects: some diet pills have the effect of increasing the body’s water discharge, calorie consumption, which may affect the scalp hair follicle nutrient intake, resulting in hair loss.