I've experimented with high protein, low fat, low carb, keto, vegan, pretty much every diet imaginable since 1998, and the one that makes the most sense to me is moderate protein and fat, and high carb with lots of fruits, veggies, and whole grains, and a low-moderate amount of meat. Low carb / keto can be good for temporarily cutting weight because you deplete your muscles of glycogen and water, but you can also run into hydration / electrolyte issues as well as lowering overall performance especially in endurance sports like cycling. I know there are studies that can conclude otherwise, but I can promise at the end of a 3+ hours road race when the attacks start coming, not having adequate glycogen or carbs is a major problem and it's hard to not get shot out the back. Worst case, myself and others I've talked to have experienced random weird heart related issues like palpitations and arrhythmia type symptoms when being totally carb depleted and most likely having electrolyte imbalances and trying to do endurance work. It's probably not dangerous, but it's not comfortable, and it's so easily avoidable. Another "side effect" of being low carb / high protein and doing lots of endurance is your sweat and clothes will smell like ammonia. Supposedly it's only temporary until your body adapts, but my body never adapted and I spent months where my cycling clothes would smell like a cat pissed in them after long rides. My suggestion, don't do it. If you need to lose weight then manage your calorie intake and improve the quality of food you eat, and spend more time on the bike!