New Delhi, Aug. 22 -- At 36, Priyanka Ghosh had finally reached her weight-loss goal. The Pune-based IT professional was exercising regularly, eating fewer calories and fitting into clothes she hadn't worn in years. Yet, instead of feeling healthier, she was constantly exhausted. By afternoon, she needed multiple cups of coffee to stay focused, and even a full night's sleep left her drained. "I thought losing weight would automatically make me feel better," she says. "It didn't."

Ghosh isn't alone. Increasingly, women are discovering that the number on the weighing scale tells only part of the story. The question is shifting from "How much weight have I lost?" to "Do I have the energy, strength and stamina to go through the day?" Experts...