Furthermore, humans develop a condition dubbed ‘rabbit starvation’[7] when they eat a diet that is low in fat and carbohydrates, and high in protein (> 35% of total daily energy intake). This is due to the inability of the human liver to sufficiently upregulate urea synthesis to meet excessive loads of protein. Consequently, hyperaminoacidemia, hyperammonemia, hyperinsulinemia, nausea, diarrhea, and even death can ensue within 2 to 3 weeks. These effects were recognized historically through the excess consumption of lean wild meat by early American explorers.[8]
A survey of 1,580 low-carb consumers published in late 2017 by the Journal of Insulin Resistance45 found that while more than 11% of respondents reported using sleep-aids before beginning their low-carb diet, less than 5% reported using them after their diet. Moreover, nearly seven in 10 reported improved quality of sleep after dieting while only 3.4% said their sleep quality had worsened.

I was a Corpsman (not a corpse-man as some recent somewhat fanatical president would say), and I can tell you many stories of Marines and Sailors who maintained restrictive diets (aka picky eaters). Most obvious was lack of sustaining energy (hypoglycemia) at mile 15 (with 80lbs of gear including a 6.5lb rifle and 200 rnds of ammo, etc.) and depletion of essential vitamins, electrolyte imbalance. They were always the first to collapse and have to hear me scold “see I told you so.” An IV of D5W usually does the trick (D is for dextrose, OMG!)
A ketogenic diet helps control blood sugar levels. It is excellent for managing type 2 diabetes, sometimes even leading to complete reversal of the disease. This has been proven in studies. It makes perfect sense since keto lowers blood-sugar levels, reduces the need of medications and reduces the potentially negative impact of high insulin levels.