The average and healthy weight loss rate is 1 to 2 lbs. per week, according to MayoClinic.com. As long as somebody is losing weight at that rate, it's really not slow. For those hoping for a faster rate, it might be time to adjust expectations.When somebody has been dieting for a long time, they might also hit a plateau. Making changes to the diet and increasing the level of activity can jump start weight loss again.
A number of things slow down metabolism and, as a result, weight loss. Crash diets are an example. Dr. Melina Jampolis writes in an article published on CNN.com that cutting down calorie intake significantly can cause a person to lose muscle mass rather than fat. Because muscle speeds up metabolism, less muscle means fewer calories burned, even for those exercising at the same pace than they did before. Skipping meals and eating less than the recommended minimum of 1,200 calories per day can send the body into starvation mode, also slowing down metabolism.
According to the 2008 Psychology Today article, "Can't Lose Weight? It's Probably Your Metabolism," a number of medical conditions can slow down or even halt weight loss. Chronic fatigue syndrome and fibromyalgia, for example, cause pain, weakness and low energy, making it difficult to keep active and thus to burn calories. Hypothyroidism, yeast overgrowth and insulin resistance can all slow down the rate at which the body burns calories. Certain medications such as antidepressants and steroids can also affect weight, according to the consumer mental health site Healthy Place.
Stress can put a lot of pressure on the metabolism. According to Psychology Today, lack of sleep can also put added stress on the body and slows down growth hormone production. Because growth hormone aids in the balance of insulin, lack of it might lead to increased hunger and difficulty processing certain foods. When a person is stressed, he might also eat more or go for comfort foods, such as sweets or high-fat snacks.