Provided that I'm not hungry, should I eat breakfast before or after a 30-minutes morning jog?
Update: There are many answers detailing opinions -- thanks! If someone could supply evidence supporting their view, I'd be even happier.
I'd say this depends on your fitness, the intensity of the workout and perhaps how much you've eaten the night before.
Assuming jogging means a running speed of about ~10 km/h or ~6 mph, I expect you don't use that much energy that you can't cope with without jogging. More importantly, low intensity workouts mainly burn through fat and anything you would eat either isn't absorbed yet or only serves you energy for a couple of minutes, which won't help you during 'longer' workouts.
Off course, if you start to feel faint at the end of the workout, you could take some glucose with you, just to recharge when you need it.
So my advise: go running and enjoy your breakfast after the workout!
I don't have any source for this but my chiropractor and my experience, but I advise against working out in the morning on an empty stomach. My goal is to burn fat through 30-45 minutes of low intensity exercise 3-4 mornings a week, but trying to burn fat without any carbs doesn't work; your body ends up eating its own protein (read: muscle). From experience, this seems to be true; I felt myself getting weaker about 3 months into my regime when I exercised on an empty stomach.
I found that getting a tiny amount of carbs into my system about 30 minutes before I exercise, then eating breakfast after, has worked well for me for about two years now.
The main problem with eating breakfast before a work out is you have to wait an hour or more for it to be digested. For jogging, a lot of people prefer to eat a carbohydrate rich meal before bed to avoid the wait in the morning.
If you aren't doing anything intense, a low speed 30 minute jog for example, this probably isn't necessary. But for more intense work outs you will use your glycogen supplies quickly without carb-loading the night before. You'll then get tired and do less, and lose lean tissue.
So the choice for running is a low intensity jog on a piece of fruit or drink, or mid-high intensity with a meal the night before.
Simple answer: exercise before, if you want to loose weight.
The New York Times has some articles citing research about this subject
The article "What is the best time of day to exercise, if my goal is weight loss?", from 2015. Cites a Belgian study where 3 groups of young men were asked to eat 30% more daily calories. First group did no exercise, second group exercised after breakfast, last group exercised before breakfast. Quote:
You might try setting your wake-up alarm earlier and exercising before breakfast. There is some evidence that working out on a completely empty stomach — or, as scientists call this woozy, wee-hours condition, "in a fasted state” — prompts the body to burn more fat and potentially stave off weight gain, compared to exercising at other times.
At the end of the six weeks, the sedentary group predictably was supersized and unhealthy, having gained about six pounds each. They had also developed insulin resistance and larded their muscles with new fat cells. The men who exercised after breakfast had also packed on pounds, about three pounds each, and developed insulin problems. But the men who had exercised first thing in the morning, before eating anything, had gained almost no weight and retained healthy insulin levels.
This one "Phys Ed: The Benefits of Exercising Before Breakfast", from 2010. Cites an Australian study. Three groups of young men, one exercised before breakfast, and the other after. They did exhausting exercise. The last group did no exercise. All of them ate a lousy and unhealthy breakfast. Quote:
The experiment lasted for six weeks. At the end, the nonexercising group was, to no one’s surprise, super-sized, having packed on an average of more than six pounds. They had also developed insulin resistance — their muscles were no longer responding well to insulin and weren’t pulling sugar (or, more technically, glucose) out of the bloodstream efficiently — and they had begun storing extra fat within and between their muscle cells. Both insulin resistance and fat-marbled muscles are metabolically unhealthy conditions that can be precursors of diabetes.
The men who ate breakfast before exercising gained weight, too, although only about half as much as the control group. Like those sedentary big eaters, however, they had become more insulin-resistant and were storing a greater amount of fat in their muscles.
Only the group that exercised before breakfast gained almost no weight and showed no signs of insulin resistance. They also burned the fat they were taking in more efficiently. “Our current data,” the study’s authors wrote, “indicate that exercise training in the fasted state is more effective than exercise in the carbohydrate-fed state to stimulate glucose tolerance despite a hypercaloric high-fat diet.”
The last NYT article: "Is Breakfast Overated?", from 2014 cites 2 studies. Each study was fairly short-term, and involved a limited range of volunteers. No exercise was involved. Results:
whatever will allow you to exercise better. chemically is no difference. food eaten right before will not be digested until way after your workout unless it it pure sugar or the like(which i dont recommend you eat for breakfast..). your nutrition a couple hours before will more likely affect your energy levels