Exogenous Obesity: The boy's accelerated weight gain trend, increased sweat production, and body odor without linear growth or other signs of puberty suggest exogenous obesity as a primary consideration. The absence of polydipsia, polyuria, or polyphagia and normal glucose levels support this diagnosis.

Hypothyroidism: Although the TSH level is within the normal range, hypothyroidism can sometimes present with weight gain and precocious puberty signs. Further evaluation of free T4 levels might be necessary to rule out hypothyroidism fully.
Adrenal Disorders: The presence of body odor and increased sweat production could suggest an adrenal disorder, such as congenital adrenal hyperplasia (CAH) or Cushing's syndrome, although the lack of other specific signs (like virilization or striae) makes these less likely.
Insulin Resistance or Early Type 2 Diabetes: Despite the absence of polydipsia, polyuria, or polyphagia, and a normal fasting glucose, insulin resistance or early type 2 diabetes could be considered, especially with significant weight gain. An oral glucose tolerance test (OGTT) or insulin sensitivity testing might be warranted.

Cushing's Syndrome: This condition, caused by excess cortisol, can lead to weight gain, precocious puberty, and other signs. It's crucial to consider due to its potential severity and the need for specific treatment.
Pseudohypoparathyroidism: This rare condition can cause early onset of obesity and might be associated with resistance to parathyroid hormone, leading to biochemical abnormalities.
Leptin Deficiency or Leptin Receptor Deficiency: These are rare genetic disorders leading to severe obesity from an early age. Although unlikely, they are important to consider due to their significant impact on the patient's health and the potential for specific treatments.

McCune-Albright Syndrome: Characterized by precocious puberty, café-au-lait spots, and fibrous dysplasia of bone, this syndrome is rare but should be considered if other signs are present.
ROHHAD Syndrome (Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation): A rare condition that presents with rapid onset of obesity in childhood, followed by hypothalamic and autonomic dysfunction. It's a diagnosis of exclusion and requires careful evaluation.

Detailed History and Physical Examination: To assess for other signs of puberty, thyroid abnormalities, or adrenal disorders.
Laboratory Tests:
- Free T4 and T3 to evaluate thyroid function fully.
- Insulin levels and glucose tolerance testing to assess for insulin resistance or diabetes.
- Cortisol levels (possibly a dexamethasone suppression test) to rule out Cushing's syndrome.
- Electrolyte panel and renal function tests to assess for any electrolyte imbalances or renal issues.
Imaging Studies: Depending on the clinical suspicion, imaging such as a bone age X-ray, abdominal ultrasound (to evaluate adrenal glands), or an MRI of the brain (to assess the hypothalamic-pituitary axis) might be indicated.
Genetic Testing: If a genetic disorder is suspected based on the clinical presentation or family history.
Consultations: With endocrinology, genetics, or other specialists as indicated by the diagnostic evaluation.