Well it depends on what you are trying to achieve, if weight loss is your goal then yes, for muscle retention it will work, but you are missing out on many other nutrients and minerals. I would suggest doing this briefly and see what your fat loss is after say a few days. Good protein shakes will contain other nutrients, but maybe not contain dietary fiber or other vitamins. I have included a list of the ingredients in Promasil Protein by Rivalus. Protein shakes are designed as a meal replacement, that is why you take them immediately after training, this is because the proteins are more bioavailable than solid food. Your muscles can begin to use the proteins straight away. Also protein shakes tend to be almost zero fat, and very low in calories. In order to lose one pound of fat, you need a negative 3500 calories. Typically if you are training and consuming two protein shakes per day, you will have 80 grams of protein and 360 or so calories, as there are 90 calories per scoop. Due to having no carbs however, you may feel lethargic keeping this diet up.
Calories 90 4%
Calories from Fat 9 2%
Total Fat 1 g 6%
Saturated Fat 0.8 g 15%
Trans Fat 0 g 0%
Cholesterol 10 mg 1%
Sodium 70 mg 7%
Potassium 10 mg 5%
Total Carbohydrate 0 g 0%
Dietary Fiber 0 g 0%
Sugars 0 g 0%
Protein 20 g 100%
Phosphorus 100 mg 25%
Magnesium 50 mg 25%
Calcium 300 mg 25%
Iron 0.5 mg 25%
Vitamin B6 1.5 mg 50%
Vitamin B12 2.4 μg 100%
Ribofl avin 1 mg 50%
Folate 400 μg 100%
Vitamin C 15 mg 25%
Vitamin D 10 μg 200%
Zinc 20 μg 200%
If you are looking to lose weight pretty fast, then this liquid diet would work, but I would only do it one day on one day off. It’s a very low calorie diet at the end of the day.
