I'm definitely no expert, and I'm relatively new to this WOL. BUT... I experience weight gain during weeks 3 and 4 of induction, plus I was getting bored with the food choices, so I took Dr. A's advice and moved on to OWL. I added higher-carb foods like pumpkin, berries, and extra veggies. This definitely re-started my weight loss. I'm in week 7 and I've lost the weight I gained earlier plus an extra pound. I think 18 months is a long time to be in induction and your body might be getting used to the foods you're eating. The principles that apply to exercise are the same principles that apply to food... if you do the same thing for too long, your body adjusts and you won't see any positive change. You need to 'shock' your system to stimulate weight loss. Good luck.