First off, fat loss is not always a liner progress. Meaning if your caloric intake is based on losing 1-2lbs a week, at times you won’t lose that much even if everything is on target.
When fat loss occurs, water retention also occurs. When a fat cell empties its triglyceride (fat) water will enter the cell since glycerol is hydrophilic meaning it attracts water. This phenomenon will mask any fat loss that is actually taking place. Women especially will have the opportunity to experience this, which is why patience is so important.
You may be at a plateau for a couple weeks and lose 1-2 lbs overnight, this is especially apparent after a night of drinking; since alcohol is a mild diuretic you will look drastically leaner. It is important to note however that this is not universal amongst all individuals, and that liner fat loss often does occur.
Galen is a trainer at Phenomenal Fitness. You can contact him at firstname.lastname@example.org