Hi Leslie, You ask an important question. Unfortunately, there are no long-term studies on this. The Internet is full of speculations, especially for those who love carbs without understanding the function of ketosis for the body and mind. Most of those claims do not make sense to me as they compare apples with oranges. Let me provide my perspective, but this is not advice.

I made ketosis a lifestyle choice for personal reasons as it provided the best balance for my metabolic and mental health. Over two decades, I did not experience any side effects. However, we are all different. Ketosis might not be suitable for everyone and not even desirable for some people. It is also risky for some underlying health conditions such as type I diabetes. Therefore, it requires support from qualified healthcare professionals.

From my experience, even people like me who don't eat any carbs and eat only one meal a day still get out of ketosis at least a few hours after the main meal when the daily insulin secretion happens. My 25% protein takes me out of ketosis after dinner, even though 75% of my calories come from healthy fats. Perhaps I should write an article about this as it is a commonly asked question. Thank you for inspiring me.

For your second question, I don't eat fruit anymore, but I am not against fruits. I used it to eat lots of berries and believe that low-sugar fruits with high nutrients can be very healthy.

Many people in ketogenic diets include at least one serving of fruit a day and still stay in nutritional ketosis, which is relatively mild.

Based on my experience and reviews, I believe that any level of ketosis (except for ketoacidosis) is helpful. The level depends on our needs and goals. As I get older I see more need for ketosis for myself. It is a personal preference.