I have recently been trying to lose weight. I walk up to 20 km a day and I usually lose more calories than I eat. Walking is my hobby and I walk for around 3 hours a day with no breaks. I was wondering because I read a while back that as long as you walk or run alot while using whey protein you can lose weight because the whey protein apperently can boost metabolism. I have a slow metabolism and I find it hard to lose weight and I was hoping that whey protein can help with it. I am 5'7" and I weigh 170 pounds. I want to drop to 150. Any helpful advice will be appreciated and thanks
You most likely don't have a slow metabolism, as this is quite rare. To lose weight you need to establish your BMR - Basal Metabolic Rate. Your BMR is dependent on your body size: the more mass you have, the more energy you use; and composition, muscle requires much more energy than fat.
To lose weight you simply need to be in a state of caloric deficit. Meaning to lose weight you have to consume less than what you use on a daily basis. Anything you eat or drink - save for water -contains energy. Hence, if you eat a caloric surplus - be it from healthy food or unhealthy food - you will gain weight. You see that in essence it is quite simple. Consume more than what you use => gain weight, consume less than what you use => lose weight.
So far, I mentioned losing weight and not losing fat. What weight (fat or muscle) you lose depends on what type of exercise you do and at what intensity. Something to consider: many studies have confirmed that one loses more fat and less muscle if they do strength training in combination with diet vs diet alone. And this is where protein becomes handy as it preserves muscle mass during a caloric deficit if one exercises the muscles.
Also, keep in mind that whey protein is a supplement, no more no less. This means it is not necessary at all if you consume enough protein via your diet alone. However, it can be an easy way of protein supplementation if you don't consume adequate amounts of protein.
Hope this was clear.
From the 50,000 foot view, weight loss is about having a calorie deficit, so the idea that you're going to "add" a food and "lose" weight is simply wrong. If you have a calorie deficit, you can lose weight while eating Twinkies (reference: http://www.cnn.com/2010/HEALTH/11/08/twinkie.diet.professor/)
Whey protein is good for building muscle. It digests quickly and causes an insulin spike which will signal your body to store nutrients and build tissue. It is the refined sugar of proteins. If you do strength training and have a calorie surplus with ample protein (whey or otherwise), you'll build muscle.