If the human body lacks fat metabolizing enzymes, it is difficult for fat to enter mitochondria and cannot be converted into energy, so no matter how you diet and exercise, you can't consume it.
Extended data
Function of enzymes: Enzymes dominate many catalytic processes such as metabolism, nutrition and energy conversion, and most of the reactions closely related to life processes are enzymatic reactions.
These properties of enzymes make the complex metabolic process of substances in cells proceed in an orderly manner, and make the metabolism of substances adapt to normal physiological functions. If an enzyme is defective due to gene defect, or its activity is weakened due to other reasons, it will lead to abnormal reaction catalyzed by the enzyme, disorder of substance metabolism and even disease, so the relationship between enzyme and drug is very close.
People's Network-Human obesity may be caused by the lack of "enzymes": it is necessary to avoid alcohol and tobacco to supplement enzymes
Baidu encyclopedia-enzyme