It may be superstition or perhaps it actually does have an affect on people while they're playing. Either way most avid golfers have an opinion of whether or not they like to eating during the round. For me I've always been more of a hot dog and a drink at the turn kind of guy but some people would rather starve themselves and head to the club house after the round. Neither are probably the best approach to sustaining energy and playing your best golf.
There should be a mix between stuffing yourself and slowing down on the course and starving yourself to potentially lose energy/strength throughout the round. Below I've listed what to eat on and off the golf course to sustain energy and play better golf.
Pre-round
Eating before a round can make a big difference. It's important to have a mix between complex carbohydrates and protein. Why? It's harder for your body to breakdown complex carbohydrates which allows you stay less hungry for longer and will keep you energized. Stay away from sugary drinks or other simple carbs that will make you susceptible to crashing. Have a larger portioned balanced meal of carbs and protein such as grains or sweet potato with chicken or steak.
During the round
For those who don't want a large meal to weigh you down, I'd suggest eating something small like a sports bar or "simpler carbs". Assuming you are walking, it's easy to burn these simple carbs off and give you more immediate energy. If you can mix in some protein that is ideal, too (hence the sports bar suggestion). If you're looking for a specific bar for golf I'd recommend the 1st and 10th tee bars by SCNA. They have bars ranging in carbohydrates and protein depending on how you're feeling. I always keep 4 in my bag in case I get hungry throughout the round and need something to keep me going.
Post-round
Hit the protein here. Another essential for my golf bag is beef jerky. Low in carbs, low in calories and high in protein. At one point I thought all jerky was created equal: dry and tough. I started eating Chef's Cut jerky products and have been hooked since. Their jerky is soft and comes in a bunch of interesting flavors (not just teryaki or mesquite). I usually eat a bag of this stuff directly after the round and have a high in protein meal later when I get home.
Lastly, you don't need to follow this strictly. You can mix in fruits, nuts or whatever the pro shop might have. Or you can just eat a burger and feel lowsy while finishing your round. But if you're looking to play well and sustain energy I'd suggest following this guide.
