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In contrast, body fat loss is gradual but you must have proper equipment to measure! You will lose body fat immediately but your shape and size may stay the same as your body retains its shape like a sponge, with the fat deposits burning out of it and becoming lower in density. Only electrical impedance or skin calipers will register these changes, as increases in water and muscle (which are much better for your heart than fat) may counter-balance your body's weight.
Remember, muscle and water are 7-8 times more dense than body fat, so you can lose inches prior to body weight. In fact, a gain in body weight is usually temporary and is the mark of a successful workout regimen because you're building calorie burning muscle.
Graphical data show is taken from an an ACTUAL CASE STUDY performed at Columbus Fit