Is IgG Unverträglichkeitstest useful for blood sugar?

The IgG intolerance test (e.g., NutriCheck I) is not useful for blood sugar management. It measures IgG antibodies to foods, but IgG is not a validated marker for food intolerance or metabolic health. Research indicates these tests often produce false positives, leading to unnecessary dietary restrictions. For blood sugar control, validated methods such as HbA1c, continuous glucose monitoring, and evidence-based dietary advice (e.g., glycemic index, fiber intake) are far more reliable. The test provides no clinically meaningful information about insulin resistance or glucose tolerance. Therefore, from a scientific standpoint, it is not recommended for this purpose. Evidence: marketing/unclear.