What would be the healthiest way to lose weight quickly and efficiently?

Healthiest not fast. when it comes to diet and weight loss, the healthiest method is not the fastest or easiest. At the end of the day, your weight is going to depend on your net calories. Assuming you are eating a well balanced diet, you could simply continue eating what you like and reduce the portions. Drink only water or natural juices. Avoid all soft drinks. Increase exercise regimen. Simple yet hard to do.