The term LIFO stands for Last in First Out, and similarly the term FILO stands for First in Last Out. Though these are the terms used in computing for the ways in which data structures are processed or in accounting for techniques of collating inventory, they are also used in fitness and body building.
The LIFO argument in fitness and weight loss
LIFO and FILO apply to fitness, weight loss and body building because of the belief that lots of experts have that what goes in last is actually the first to leave. So, the fat that you gained most recently is that which you will shed most quickly. The fat that is stored for the longest time, which you have carried around for the longest duration, is the fat that will come off last, according to this hypothesis.
This theory is used to explain why it is that the fat off the abdomen is the last to come off. Since when we first start to gain weight we tend to deposit rather a lot of it around the waist (particularly men), this is the weight; the abdominal fat that is hardest to budge and the last to be shed.
People who are trying to lose weight also experience that the fat is lost in much the same pattern that they gain it when that pattern is reversed. So if a woman started to accumulate fat first on her thighs, hips and buttocks area then this is the area of her body that will most stubbornly hold on to the fat.
The argument against LIFO
Not everyone contributes to the LIFO theory in fat loss and fitness however; nor does everyone experience the same sort of fat loss. As we gain weight in different ways and areas, we also lose weight in different ways.
Also there is the concept of fat redistribution that occurs when you are part of a fitness or weight loss program. A person can appear to have lost weight or may look better not because of fat loss but due to fat redistribution.
So in conclusion, LIFO is a concept that seems to be at play in a lot of cases, but in others, this predictable pattern is not observed.