Weight loss, in the context of medicine, health, or physical fitness, refers to a reduction of the total body mass, by a mean loss of fluid, body fat (adipose tissue), or lean mass (namely bone mineral deposits, muscle, tendon, and other connective tissue). Weight loss can either occur unintentionally because of malnourishment or an underlying disease, or from a conscious effort to improve an actual or perceived overweight or obese state. "Unexplained" weight loss that is not caused by reduction in calorific intake or exercise is called cachexia and may be a symptom of a serious medical condition. Intentional
Intentional weight loss is the loss of total body mass as a result of efforts to improve fitness and health, or to change appearance through slimming. Weight loss is the main treatment for obesity, and there is substantial evidence this can prevent progression from prediabetes to type 2 diabetes with a 7-10% weight loss and manage cardiometabolic health for diabetic people with a 5-15% weight loss.Weight loss in individuals who are overweight or obese can reduce health risks, increase fitness, and may delay the onset of diabetes. It could reduce pain and increase movement in people with osteoarthritis of the knee. Weight loss can lead to a reduction in hypertension (high blood pressure), however whether this reduces hypertension-related harm is unclear. Weight loss is achieved by adopting a lifestyle in which fewer calories are consumed than are expended.
Methylmalonic acidemia, also called methylmalonic aciduria, is an autosomal recessive metabolic disorder that disrupts normal amino acid metabolism. It is a classical type of organic acidemia. The result of this condition is the inability to properly digest specific fats and proteins, which in turn leads to a buildup of a toxic level of methylmalonic acid in the blood.Methylmalonic acidemia stems from several genotypes, all forms of the disorder usually diagnosed in the early neonatal period, presenting progressive encephalopathy, and secondary hyperammonemia. The disorder can result in death if undiagnosed or left untreated. It is estimated that this disorder has a frequency of 1 in 48,000 births, though the high mortality rate in diagnosed cases make exact determination difficult. Methylmalonic acidemias are found with an equal frequency across ethnic boundaries. Symptoms and signs
Depending on the affected gene(s), this disorder may present symptoms that range from mild to life-threatening. Stroke
Progressive encephalopathy
Seizure
Kidney failure
Vomiting
Dehydration
Failure to thrive and developmental delays
Lethargy
Repeated yeast infections
Acidosis
Hepatomegaly
Hypotonia
Pancreatitis
Respiratory distress

Cause
Genetic
The inherited forms of methylmalonic acidemia cause defects in the metabolic pathway where methylmalonyl-coenzyme A (CoA) is converted into succinyl-CoA by the enzyme methylmalonyl-CoA mutase.Vitamin B12 is also needed for the conversion of methylmalonyl-CoA to succinyl-CoA. Mutations leading to defects in vitamin B12 metabolism or in its transport frequently result in the development of methylmalonic acidemia.This disorder has an autosomal recessive inheritance pattern, which means the defective gene is located on an autosome, and two copies of the gene—one from each parent—must be inherited to be affected by the disorder.