Beating Obesity, The Hormones Regulation, A Practical Guide, Dr Hatem Maher. People struggle to lose weight or prevent weight gain, while following their keto diet guidelines strictly. Weight gain and obesity are driven by hormones - in everyone - and only by understanding the effects of obesity hormones — insulin, cortisol, leptine, grehlin, peptide YY — and improving our insulin sensivity can we achieve lasting weight loss.