Method and system to provide therapy for obesity, gastric motility, or to induce weight loss comprises ablating the gastric tissue around the "pacemaker" region of the stomach, and electrically pacing the stomach with a pulse generator/stimulator to control the electrical activity of the gastric muscle. The ablation to the gastric tissue may be from the epigastric side, or may be from inside the stomach. The ablation may be performed utilizing any one of: radiofrequency catheter ablation; radiofrequency catheter ablation using an irrigated tip catheter; microwave ablation; cryoablation; high intensity focused ultrasound (HIFU) ablation; and laser ablation. The ablation of the "pacemaker" region of the stomach may be partial or complete. A gastric pulse generator/stimulator is implanted to provide electrical pulses to the stomach. The function of the gastric stimulator after complete ablation of the pacemaker region, is to provide a basic electrical rhythm (BER) to regulate and control electrical activity of the stomach. Alternatively, if partial ablation is performed the function of the gastric pulse generator/stimulator is to enhance the residual basic electrical rhythm (BER), or to interfere with the residual basic electrical rhythm (BER).