If you've gained back fat after losing weight, you aren't alone. And, as it turns out, yo-yo dieting might not be the direct cause of the sudden fluctuation in fat distribution. A new study published by scientists at ETH Zurich explains that fat cells "store memories of obesity in their cell nucleus," according to a statement from the Swiss university. As a result, the cells retain these memories even after you lose weight, making you more susceptible to future weight gain. I...