Your body weight naturally changes from day-to-day, and these small fluctuations are very normal. In fact, weight loss is not at all linear. It can go down, stay the same, or even go up throughout your plan.
Three factors that may influence weight loss (or weight gain):
Metabolism - Metabolism is the amount of energy required to maintain life. Your metabolic rate adjusts constantly in response to many factors, including body composition, exercise type, temperature, hormonal levels, illness, or stress. When your metabolism changes, it may cause you to burn more or less calories for your daily needs.
Digestive issues - Carrying around food in your digestive tract can cause artificial weight gain. Prevent constipation with proper hydration and fiber intake.
Hydration level and water retention - It is quite common for your body weight to fluctuate in excess fluids depending on diet (higher carbohydrate intake or sodium intake) or during menstruation for women. Carbohydrates contain water molecules and increase glycogen stores in the liver. A meal high in carbohydrates might cause the scale to go up in the morning, but fluctuate back down throughout the day. Hormonal changes throughout the month can also cause water retention and weight gain. Stay properly hydrated to prevent your body from retaining excess fluids.
Remember, fat loss does not always mean weight loss. As you replace more body fat with muscle, you may not see the numbers drop on the scale, but you will see your body composition change, clothes fit better, and/or different body parts feel tighter. This is why we stress the importance of photo documentation throughout your plan.