- Sensationalized aspect of news reporting – they want to pull you in!
- Journalists that don’t have a background in understanding health information and body biochemistry are attempting to sift through information they may not fully understand
- There’s limited time to fact check
- Only utilizing the abstract/press release, and not looking at the remainder of the article
- Journalist and publication bias and background
This morning, I’ve seen several news outlets break with the story “Lose Fat Faster Before Breakfast!” These articles talk about a study that was published this week in the British Journal of Nutrition, which looked at the impact of 4 different combinations of activities/breakfast regimens on metabolism and appetite. They looked at fasting then resting, fasting then exercise, breakfast then resting, and breakfast then exercise. The reports are abundant that you’ll burn 20% more fat when skip breakfast and exercise.
Ugh. Not quite. Perfect example of sensationalized media.
I went ahead and got a copy of this study. While it’s interesting, here are my issues (and I should note many of these issues are addressed by the researchers, they’ve just been left out of media reports):
1) The study was done on just 12 men. Not a very large sample size to draw conclusions.
2) Getting deeper – this was conducted on 12 physically active men. Physically active was defined as at least 30 minutes of physical activity, 5 days per week. Considering the majority of our country is overweight/obese and many people even of normal weight are not regularly active, I’m not sure these results can be generalized to the remainder of the population.
3) The articles about this study are reporting that skipping breakfast does not lead to overcompensation of calories later, and eating breakfast led to a greater overall number of calories consumed. However, in this study, they were only looking at energy intake from the breakfast (or lack thereof), recovery drink, and lunch. There’s no information on the remainder of the day, and we know that people who often skip breakfast end up overcompensating later in the day.
4) Whenever you are exercising, your body is using a mixture of carbohydrate and fat to fuel your exercise. This study found that breakfast increased the amount of carbohydrate used as a substrate and decreased the amount of fat utilized as a substrate. However, this difference was not very large. And most exercise physiologists will argue that it is the total rate of energy expenditure, not the exact percentage substrate utilization, that is important for issues like weight management and health (now, there are other schools of thought particularly for certain training purposes, but I'm not going to get into those here for the sake of simplicity). In fact, in this study when we look at the overall number of calories burned, it was actually higher in the breakfast exercise trial compared to the fasting exercise trial:
- Breakfast then exercise = 873 calories (3003 kJ) burned (mean)
- Skip breakfast then exercise = 717 calories (3655 kJ) burned (mean)
5) The study did not include any data on the perception of exercise difficulty. I know if I’m going out for an hour run, I’m going to feel better and more comfortable if I’ve had some breakfast earlier. If the hour of exercise feels significantly more difficult without breakfast, that may deter people from exercising or sticking to a training regimen, which would not be good.
6) Many articles reporting on this fail to mention that the exercisers did have a recovery drink afterward. So for those who did skip breakfast, they did still have a mini-meal after their workout and before lunch.
The bottom line: Do what feels right for your body and is geared towards your goals. What I’d recommend you definitely avoid is skipping breakfast, exercising, and not eating anything until lunch. Odds are if you don’t overcompensate at lunch, you probably will later in the day. If you hate working out with food in your stomach, maybe you want to do a moderate morning workout on an empty stomach and then eat breakfast afterward. If breakfast helps you power through your workouts, though, it’s probably a good idea to eat it. For example, if you’re an endurance athlete getting ready for a 2 hour run, your body needs that fuel.
Share with us: Do you eat breakfast before working out?