1. Drinking too much alcohol or pop. Although there is no fat in most alcoholic drinks they contribute to fat gain because of the calorie content of alcohol. The energy in alcohol must be burned immediately, while your body is busy burning the extra calories from the drink your body will have no choice but to store most other the calories ingested from healthy meals.
Alco-pops are even worse they supply calories through the alcohol AND tons of extra energy through the added sugars. Even normal pop or soda should be cut out or at least severely restricted because of the effects on blood sugar levels. You should be drinking more bottled water instead of soda if you want to keep losing fat weight.

2. Too little exercise or less effective routines. We all know we need to exercise in order to stay trim but many people still don