Con: Results can vary depending on how much fluid you drink. By drinking more water, you dilute the concentration of ketones in the urine and thus a lower level of ketones will be detected on the strips. The strips don’t show a precise ketone level. Finally, and most importantly, as you become increasingly keto-adapted and your body reabsorbs ketones from the urine, urine strips may become unreliable, even if you’re in ketosis.
Following a ketogenic diet puts your body into a state of “ketosis,” which is a metabolic state that occurs when most of the body’s energy comes from ketone bodies in the blood, rather than from glucose from carbohydrate foods (like grains, all sources of sugar or fruit, for example). This is in contrast to a glycolytic state, where blood glucose (sugar) provides most of the body’s fuel (or energy).
When it comes to meat, there’s not much to avoid. You should always make sure to purchase meat with fat and void lean cuts, as this will not help you lose weight. Remember fat is your friend. Fat is needed so your body has fat to burn and not sugar. When you are on a low carb diet, you are not fueling your body with sugar, so make sure you eat plenty of fat. If you don’t have fat to burn, your body will start burning glucose (even if you have fat stores). Your body needs to know that it never has to worry about not having enough fat.
One cup of 2% fat plain Greek yogurt has about 10g net carbs. If you plan to restrict yourself to 20g net carbs a day, that will already be half of your allowance. So most people avoid yogurt or only eat a small amount of it. For example, I use 1 cup of Greek yogurt to make slow cooker chicken tikka masala, but since it’s spread out among 4 servings, its carb impact per serving is low.
A small Feb. 20, 2017, study looked at the impact of a six-week ketogenic diet on physical fitness and body composition in 42 healthy adults. The study, published in the journal Nutrition & Metabolism, found a mildly negative impact on physical performance in terms of endurance capacity, peak power and faster exhaustion. Overall, researchers concluded, “Our findings lead us to assume that a [ketogenic diet] does not impact physical fitness in a clinically relevant manner that would impair activities of daily living and aerobic training.” The “significant” weight loss of about 4.4 pounds, on average, did not affect muscle mass or function.