I’m gonna do a very annoying doctor thing and say that every diet has its own disadvantages and benefits.
However all things considered, I have chosen a low carb/relatively higher fat diet for myself after weighing the pros and cons, and also just for the fact that it suits my lifestyle and I genuinely like proteins more than carbs. I mean who wouldn’t choose a good steak over rice any day?
Disclaimer that what you’ve asked is probably in the territory of a nutritionist/dietician rather than a doctor, but I shall attempt to address your questions based on what I remember from med school and my sport medicine course a long time ago:
1. Deprive energy to brain as can only accept sugar as energy not protein
Yes, the brain cannot use proteins as energy. It uses glucose.
But fat, protein and carbs can ALL be broken down into glucose. It’s just much easier for your body to turn carbs > glucose.
You also have other forms of energy stored away in your liver and muscles, in the form of glycogen, which can again be turned to glucose easily, so I wouldn’t worry too much about depriving your brain of glucose.
Anyway – a simple solution is to not restrict yourself to protein – I eat animal fat, and good sources of fat – olive oil, salmon etc. I also eat small amount of carbs.
2. Cause excessive ketones to be formed and in a long run cause liver/kidney problems.
This will not happen if you are a HEALTHY person with no preexisting kidney problems.
There was a review study that looked at all of the published research on high-protein diets and kidney disease. The authors concluded that while high-protein diets can be harmful for those with kidney disease, they do not harm the kidneys in healthy individuals. Other studies and links here: (7, 8, 9)
3. What is the most effective method to lose weight healthily?
Diet plays 80% of the role in losing weight, exercise plays 20%.
Simple maths equation – what you burn must be more than the calories you eat. My endocrine professor at school used to say to his patients that if you are not constantly hungry – it means you are not losing weight.
Your body has an uncanny mechanism called homeostasis which basically tries to keep everything the same – your weight, body temperature etc etc. ie if you started losing weight, your body goes SHIT WE NEED TO EAT MORE, hence you get hunger pangs, and end up eating more the next day unknowingly. Which is what makes it so challenging for many overweight patients to lose weight.
If I were you, I would stick to a clear diet plan, and regular exercise regime. I like a low carb diet for losing weight.
You could also consider seeing a sport medicine doctor who has expertise in helping people lose weight safely.
Cheers
