When you are trying to lose weight, avoid mindless eating. Slow down and pay attention to what you are doing when you have something to eat. Do not just sit in front of the TV eating directly out of the package and barely tasting what you are eating. You will consume much less food if you are careful to really think about it first.
Don't be disappointed by setbacks. Everyone has highs and lows. Sometimes weight loss will slow down or speed up. Pay attention to your activities and diet, but under no circumstances give up on your goals. Human beings are not machines and certain events can slow down or increase weight loss.
Weight loss that is not intended could be due to medical issues. The thyroid may be off-kilter and that can cause rapid loss of weight, by speeding up the metabolism. A simple blood test can help you determine if your weight loss is due to an unknown medical condition.