Having the proper fuel to finish the round

Length of time it takes to play golf requires you to be proactive in hydration and refueling your body with the proper food to continue to keep your energy levels high from the 1st hole through the 18th hole. 
For instance, if you weighed 160 pounds, walked and carried your clubs for 18 holes you would have burned approximately 2000 calories by the end of the round.  If you weigh more you'll burn more.  I would say that's a pretty impressive weight loss program.  What this stat says is that you need to fuel your body before, during and after the round.  Playing a round of golf takes 4-5 hours.  If you're burning 1000 plus calories you're going to need to re-hydrate and re-fuel sometime during the round.  If not you're energy levels and focus are going to be shot before you finish. 
Water has and will always be the king of hydration fluids.  But part of avoiding dehydration is keeping  your electrolyte levels up.  Postassium, Calcium, Magnesium, Sodium and Chloride are the key components to maintain your electrolyte levels.  Gatorade has long been the favorite drink to help in this area but it really has way too much sugar and not that much in the way of electolytes to help.  For instance, it would take 2 1/2 servings of Gatorade to match the potassium of one banana.
Trace Minerals is a company found in many health food stores that is a wonderful electrolyte replenishment aid.  Adding a packet to water before, during and after the round will go a long way to staying properly hydrated. 
Great snacks for the course include nuts, beef jerky, fruits and fitness bars.  Just check the labels to minimize sugar and get a good quality of beef jerky. 
Staying on top of your re-fueling and re-hydrating may just be the missing link to finishing off that good round of golf.