There is about 5–7 calories in the average teaspoon of jizz. It also only contains zinc, fructose sugar, protein and a couple of other bits and pieces. The average male requires between 2000–3000 calories per day to maintain their weight. Therefore, if you’re a dude, you would be required to wank off and drink the semen on around 286 men per day to get enough calories, that is providing that they ejaculate a teaspoon worth of valid semen and have not had other ejaculations throughout the day and each teaspoon contains 7 calories. You should become vitamin and mineral deficient very quickly, along with many other nutritional requirements. You would probably find yourself vomiting as your stomach is not designed to drink substances like that and the salty, clinging sensation may well make you throw up. If you have a strong enough mouth, stomach and wrist to maintain this new diet fad, then more power to you.