Multisystem complications of medical weight loss: urinary tract stones, osteoporosis, and neuroimmune damage

I. Urinary Tract Stones The incidence of urinary tract stones in my country is 1%–5%, with a relatively higher incidence in southern regions. Urinary tract stones refer to stones that occur in the kidneys, bladder, ureters, and urethra, with kidney and ureteral stones being the most common. These stones form crystals due to the concentration and precipitation of urine. Based on their composition, they are mainly classified into five categories: calcium oxalate stones (the most common), calcium phosphate, uric acid, magnesium phosphate, and cystine stones. During ketogenic diets and excessive dieting, a large amount of ketones are produced. Excessive ketones in the urine reduce the clearance of uric acid, inducing hyperuricemia or gout, which is a significant cause of uric acid stones in people trying to lose weight. In addition, low-carbohydrate diets and the Paleo diet require the consumption of large amounts of animal protein, which can also cause elevated uric acid levels; simultaneously, too low a carbohydrate intake can trigger ketosis, increasing the risk of uric acid stones. Nutritional prevention measures: 1. Adequate water intake. This is a prerequisite for reducing various risks. 2. Low-sodium diet. It is recommended that daily sodium intake not exceed 1500mg. 3. High-calcium diet. Adequate calcium intake can reduce the risk of calcium oxalate stones. Dietary calcium can bind with oxalate in the digestive tract and be excreted. 4. Limit oxalate in foods (such as spinach, potato chips, etc.). 5. Limit animal products. 6. Supplement with probiotics to regulate the balance of urinary tract flora. 7. Maintain a balanced diet and lose weight scientifically. II. Osteoporosis and Growth Disorders Osteoporosis is a metabolic bone disease in which patients experience decreased bone density and strength, increasing the risk of fractures. Most cases of osteoporosis associated with poor weight loss are caused by low body weight and estrogen deficiency in women. Estrogen promotes osteoblast differentiation and assists in calcium metabolism. When estrogen is deficient, osteoclast production increases and activity is prolonged, leading to decreased bone density. Amenorrhea affects 70% of women with anorexia nervosa (AN), and their fracture risk is three times higher than normal. Prevention and treatment recommendations: Consume sufficient dietary calcium, vitamin D, and highly bioavailable protein; maintain a low-salt diet. Children and adolescents in their developmental stage who are picky eaters or have anorexia are prone to improper energy and nutrient intake, leading to developmental delays. Regular anthropometric measurements and assessments should be conducted. Third, weakened immune system function and skin damage: Nutritional deficiencies can impair immune function. Extensive data shows that people with insufficient energy intake have an increased risk of infectious diseases. Losing 2kg in two weeks significantly affects the phagocytic activity of macrophages. Insufficient protein intake also affects the proliferation and maturation of immune cells. Microscopically, vitamins A, E, B₆, B₁₂, folic acid, C, and minerals such as zinc, iron, copper, selenium, and manganese play a crucial role in the formation and repair of immune function. However, excessive supplementation with a single micronutrient can also damage immunity and increase the risk of infection. Nutritional imbalances caused by improper weight loss can also lead to dry skin, peeling, dermatitis, and hair loss. Healthy skin requires protein, vitamins A, C, E, and zinc to promote collagen synthesis; these nutrients also have antioxidant, anti-inflammatory, and UV-damage repair effects. IV. Decreased Nervous System Function: Malnutrition and micronutrient deficiencies caused by excessive dieting can also affect nervous system function. Malnutrition and low weight in the elderly may induce dementia and increase mortality; malnutrition and weight loss in patients with cognitive impairment can also accelerate neurodegeneration. Supplementation with DHA, EPA, and folic acid can significantly improve cognitive ability and memory in healthy individuals and Alzheimer's patients, and adequate intake of vitamin E can also prevent Alzheimer's disease.