TNF and Hyperinsulinemia: Different rat strains with distinct fructose ingestion protocols are reported in the literature and, in all cases, fructose has been observed to induce MS features such as moderate hypertension, glucose intolerance, hyperinsulinemia, insulin resistance, dyslipidemia (hypertriglyceridemia, hypercholesterolemia), altered cytokine and adipokine status (altered tumor necrosis factor-alpha (TNF-α) and leptin levels, e.g.), decreased melatonin production, and/or increased body fat and/or body weight [15–20].