Actually, quite the contrary. My immune system has gotten stronger as of late. Two months ago, i was sick for a week with the flu, got better for 2 days, then caught a cold. I recreated the same conditions for myself a few days ago, and i havent shown any signs of illness or fatigue that isnt assosociated with insomnia.
The bars and shakes provide all the nutrition I need, and I have one or the other every three hours to keep my metabolism active. Combine it with at least 30 minutes to 1 hour of cardio 3-5 times a week, 2 litres of water daily, supplements of cayenne pepper for stimulating the metabolism, vitamin B-12 for energy, and at least 6 house of sleep a day, and that's the diet I'm on. It helps that for the duration of then diet I have stayed away from alcohol, caffeine, and tobacco.
Normally, yes, this diet is very dangerous. But I did my research, and made sure to keep safe with it. I had blood work done beforehand to make sure my body wasn't decifient in anything, got supplements for low Vitamin D levels (not a big fan of the sun) and so far it's time amazingly well. The hard part comes next week, when I slowly reintroduce foods that have different tastes and nutritional benefits, much in then way you slowly, carefully give measured amounts of food to a malnourished child, rather than letting tthem stuff their faces and going into nutritional shock.
Besides, I not only feel and look a lot better, the health benefits are already showing. 2 months ago I was borderline diabetic, and now it's not even a concern. All I have to look out for is blood pressure levels- I play a lot of video games, and when I lose I get quite the temper.
But to reiterate, the 'food' I am consuming is nutritionally sound, low in calories/carbs/sugars, and high in protein, iron, and other minerals the body needs but can be difficult to come by. All I really need at this point is more Vitamin D- my diminished levels have caused me to get dizzy very easily, and since its too cold to go outside, I need to see a doctor to get a refill on the supplements I was taking.
Fact: most people find it boring, but I like to read medical textbooks and articles in my spare time.