When fat is mobilized from adipose tissue without concurrent oxidation, there is no net reduction in adipose tissue mass.

Study: Higher baseline fat oxidation promotes gynoid fat mobilization in response to a 12 week exercise intervention in sedentary, obese black South African women.

Your body can pull fat out of storage, but if it doesn’t burn that fat for energy, the fat just sits around. This study showed that when people exercised and burned more fat, they lost fat — but if they didn’t burn it, they didn’t lose any.

Study: Adipose Tissue Resistance to the Antilipolytic Effect of Insulin and Niacin in Humans With Obesity.

If fat is pulled out of fat stores but not burned for energy, your body doesn’t lose fat — and this study shows that in obese people, fat keeps getting released even when it shouldn’t, meaning it just sits around instead of being used up.

Study: Fat Oxidation, But Not Subcutaneous Adipose Tissue Lipolysis, Differs Between Males and Females During a Treadmill‐Based Heat Tolerance Test

The study shows that just breaking down fat isn't enough to lose weight — your body also needs to burn it for energy. When people broke down fat but didn’t burn it much, their fat stores didn’t shrink.

Study: Spot reduction: why exercise probably can’t help you target fatty areas of the body

You can't lose fat just from your belly by doing crunches—your body burns fat from all over when you use more energy than you eat. Mobilizing fat from one spot doesn't make it disappear there unless your body actually burns it for energy.