Yup. Current weight is a sum of several variables: body fat, muscle, water, and digestive track contents. Nearly all day to day variation (up to three pounds in my case) is water. The long term trend is mostly body fat, but I need at least a week and sometimes up to three to see the underlying fat changes. Sometimes my weight will remain almost level for two weeks, and I'll then I'll drop 5 pounds in a few days, and wind up right back where the underlying calorie consumption said I would.
By using a one day window, the author has mostly detected things that affect water weight. Carb intake is a huge driver of water weight because of muscle glycogen replacement, which includes a huge amount of water.
This isn't to knock ketosis: If you enjoy eating that way and it encourages you not to overeat, then it's probably a great strategy for you. Might be worth checking your lipids after a few months though: I've heard of the rare person who tries the Atkins diet and shoots up to 400+ cholesterol.
By using a one day window, the author has mostly detected things that affect water weight. Carb intake is a huge driver of water weight because of muscle glycogen replacement, which includes a huge amount of water.
This isn't to knock ketosis: If you enjoy eating that way and it encourages you not to overeat, then it's probably a great strategy for you. Might be worth checking your lipids after a few months though: I've heard of the rare person who tries the Atkins diet and shoots up to 400+ cholesterol.