Is it true one must consume calories as a breakfast for optimal metabolic performance? Or, could one do the calorie consumption later in the day without negative effects?
Depends what for.
Fat loss, no.
Muscle, when it comes to protein…a little, probably best to have a few meals but intermittent fasting with the right amount still works well, it’s just not optimal.
For endurance performance and lifting, when it comes to carbs, yeah. You replenish muscle glycogen stores faster after exercise. You also need the fuel for performance around 2-4 hours before exercise. If you were say doing something for a few hours you may need some sime carbs in the middle E.g. If you run very long distances.
For sleep disruption, probably don’t wanna eat too close to bed as your body should be focusing on sleep processes but is using some of it’s bandwidth for digestion.
I wouldn’t overthink it.
I lost 60 pounds and ate 3 meals a day- breakfast, lunch, and dinner. I tracked my calories and it didn’t seem to matter what time of day I ate so long as I stayed within my calorie budget. I also exercise 3 times per week.
Yes absolutely, at least in abstract. However, this is one of those things that is far less important than people make it out to be. If you are trying to lose weight, and you eat at a calorie deficit, you will lost weight. It doesn’t matter at all when you consume them.
That said, eating before bed can impact sleep quality, and eating in the morning can help reduce hunger cravings throughout the day. At the end of the day, do what works best for you. It’s within the last 1% of a perfect diet, so unless you’re doing the other 99% of things right, it simply won’t have much of an impact.
Chrononutrition is an interesting and newer field of research.
At the very least, it’s probably not a good idea to consume the bulk of your calories before you sleep unless you’re intentionally trying to mess with your circadian rhythm.
What do you mean by ‘metabolic performance’? If you’re talking weight loss, there are some studies that show that front-loading calories can help with weight loss. Although there was a study that came out last week (don’t have the link on me) that looked at overall weight-loss performance in an RCT. It was an extremely rigorous study and per that study, there were no differences between the front-loaded calorie group and the back-loaded calorie group, in terms of weight loss.
I personally don’t think there’s much of a difference - it really depends on what works for you. This is purely anecdotal, but I violate pretty much every rule out there on time-based eating. I eat alot of my calories in the hour or 2 before I got to bed (last night, e.g., that included darn near 1000 calories), I eat before I work out, and I eat pretty much all day long. I am a bulk eater, so I go for low-calorie-dense foods that I eat pretty much all day long. My daily calorie intake is somewhere around 2500 - 2600 calories, and I’m 5’7”, male, 54 YO, and I weigh right around 135 - 136 pounds. I work out, vigorously, for 60 - 75 minutes per night, 7 days a week, which is why my calorie intake is as high as it is given my age and weight. I’m formerly obese, and have lost between 60 and 65 pounds overall, and have been at a healthy weight for the last 13 years.
I know many will advocate that you shouldn’t eat right before bed. I know many will advocate not working out on a full stomach. I’ve found no ill-effect from me following neither of those suggestions.
Ideally you want to spread things out evenly throughout the da for the sake of digestion. But there won’t be any negative effects if you have your calories later in the day. Except maybe you’ll wake up with a higher number on the scale due to digestion not being complete
If you’re doing a workout before lunchtime where you will exercising at a moderate-high intensity (anything more than a jog on the treadmill for most people), then having breakfast will help improve the quality of this workout (i.e. glucose is required for activity that exceeds your anaerobic threshold).
Aside from this situation, there is no reason that you MUST eat breakfast from purely a metabolic standpoint. Calories at one time of the day are worth no more than calories at another, they all translate to the same amount of fat storage if you are in a calorie surplus. So to answer your question, if you eat the same amount of calories later in the day instead it shouldn’t have any negative implications for health (assuming you don’t have any pre-existing metabolic conditions such as diabetes).
However, there might be some practical implications on diet quality when skipping breakfast. Breakfast foods are often (not always) more nutritious than other meals (I’m talking about rolled oats, fruit, eggs, wholegrain bread rather than refined cereals), so you might replace the ‘gap’ left by skipping breakfast with lower value foods later in the day such as through increased snacking. Though this will vary person to person, as does anything in nutrition.