It all sounds great in theory however ketosis when you’re awake is not good for the body and can lead to fatigue, exhaustion and lethargy. Your body and especially your brain’s primary fuel source is carbs, especially the glucose (sugar) in your blood to give it energy to keep you awake and functioning throughout your day. They are also important for super intense bursts of energy when your body needs the calories really fast, this could be sprint exercise, reflexes from a fall or being startled by an obnoxious kid.
During exercise your body will consume carbohydrates but as stated above, they will be saved for when you really need a good burst of energy. The first 2 minutes of moderate to high intensity exercise your body will use carbs, from there it will then start to burn fat through oxidative phosphorylation. Not only is this process much more efficient to convert fat into energy but it is much safer to and does not produce ketones which are a by-product of ketosis that can have negative health effects.
The body will then store your remaining carbs and increase your blood sugar for more intense periods of exercise (say if you’re running sprints, powerlifting or high intensity interval training) but it won’t be able to sustain that level of exercise for very long, hence your muscles burn, you run out of breath and have to slow down or stop and rest. This is a much healthier and more effective way to train your body and best utilize your body’s carbohydrate and fat stores when trying to lose weight.
When you starve your body of a vital nutrient such as fat, carbs or even water it’ll hold onto what it has and slowly burn through it to sustain itself. This is the idea behind low carb/ low fat diets as a quick and easy way to lose weight. However this means your body will not be able to operate at it’s preferred level and effectively slip into a “vital functions only” mode. Hence you will see decreases in abilities, brain function, energy and even mood. Your body will work to maintain the carb/fat stores for as long as possible and ration it out so you will retain what you have instead of losing it.
Basically what I am saying is that low carb/ low fat diets are not an effective or sustainable way to lose weight. It is important to consume everything in moderation and to focus more on the quality of your food over the quantity. Eating whole grains, fruits, nuts and even vegetables are all very good quality carbohydrates to consume. You want foods that are “nutrient dense” which are foods that are heavy on vitamins, minerals, fiber and antioxidants. In addition these carbohydrates are “complex” which are carbohydrates that contain more nutrients such as vitamins, fiber and minerals that the body can absorb and benefit from.
Refined and process carbohydrates should be limited; they are found in many breads, sweets, pastries and such. Food ingredients primarily ending in “ose” such as glucose, sucrose, and lactose are sugars. They’re not necessary bad for you however consuming too much is a bad thing so it’s important that you are eating sugars in moderation and preferably contain other vitamins, minerals, fibers, anti-oxidants and water.
The time of day that you eat doesn’t matter as well, many people think it’s not okay to eat after 8 or 9pm due to perceived weight gain effects but that is only a myth. The problem occurs not in the time of day but the amount people are eating throughout the day, eating more late at night can lead to overconsumption so it’s important to limit your portions when snacking late night.