Insulin is a hormone in our body that controls the storage of fats and proteins. People with diabetes experience an insulin deficiency, which results in their bodies being unable to effectively store and use proteins, fats and carbohydrates. Since they are unable to store the needed nutrients, their appetites will increase while their weight decreases. For type 1 diabetes, if the insulin levels are not medically corrected, the fat tissue and amino acids in the muscle tissue are targeted, resulting in a loss of fat and muscle mass. This can cause a drastic decrease in overall body weight, but it is extremely rare and the diabetic will develop many other illnesses by the time such a weight loss occurs.
Ketones are formed in our bodies when fatty acids and amino acids are broken down. Ketoacidosis occurs when high levels of ketones are present in the body and the body does not produce enough insulin to break the ketones down. Ketoacidosis is an extreme form of ketosis, which occurs in any otherwise healthy individual who has been fasting and results in weight loss.
Dehydration is a common symptom among diabetic patients. Diabetes causes an increase in blood sugar, which in turn leads to increased amounts of glucose in the person's urine. Excess urinary glucose will lead to increased amounts of urine being released and can lead to dehydration. If the body loses sufficient amounts of fluids, this can lead to unintentional weight loss. Diabetics with this type of weight loss experience increases in thirst.
Fluid loss and high glucose levels alone can both cause weight loss in a diabetic. When those factors are combined in diabetes, a person increases his risk of developing cachexia. Cachexia is extreme weight loss accompanied by atrophied muscles, fatigue, loss of appetite and general bodily weakness in anyone who is not consciously trying to lose weight. If the diabetic has secondary diseases such as Addison's disease, tuberculosis or pancreatic cancer, the possibility of developing cachexia will be significantly higher. The weight loss caused by cachexia cannot be reversed by increasing the intake of calories. Only certain types of drugs, such as steroids, are shown to be effective in treating cachexia.