Saturated fats in food will pack on more visceral fat than polyunsaturated ones, according to a 2014 Swedish study. When subjects ate 750 more calories daily for seven weeks, either in the form of palm oil (saturated) or sunflower oil (polyunsaturated), the former gained more visceral fat while the latter gained more muscle mass and less body fat. The study authors believe different fat types can impact both the way your body forms fat and stores it. What’s more, including healthy fats in your meals can make them more satiating and keeps hunger at bay.
Too little sleep or too much sleep can throw your stress and regulatory hormones out of whack, and may lead to weight gain. A single night of sleep deprivation can increase levels of ghrelin (a hormone that promotes hunger), making you more likely to overeat the next day. Reduced sleep may also lead to fatigue during the day (duh) and less physical activity, which may be another reason why people who regularly don't get enough sleep tend to gain weight.
Why do people get different results with this diet plan? Medical conditions can play a big role in weight gain or loss. It is important to understand any medical conditions you may have before going on a diet. Many different issues can lead to abnormal weight gain, including thyroid issues. If this is a concern for you, read this article on hypothyroidism and its effect on weight. Mental health issues can also lead to weight gain or loss. If you struggle with anxiety, you may experience abnormal weight gain. Make sure to ask your doctor for advice about how to manage the anxiety without over-eating.