We've all undoubtedly heard that breakfast is the most important meal of the day. But many of the studies that underpinned that marketing campaign were funded by--you guessed it--cereal manufacturers like Quaker and Kellogg. Unfortunately, the more objective research does not show a causal relationship between regularly eating breakfast and weight loss. While fueling up first thing may not kickstart our metabolisms into gear, there are other factors to consider when deciding when to break the overnight fast.
Circadian rhythm. Our body has a natural circadian rhythm regulated by the hypothalamus and largely synced to light/dark cycles. We often associate this cycle with sleep patterns, but our circadian rhythm also regulates metabolic processes such as appetite, digestion and metabolism of fat and glucose. For example, studies have shown that we expend more energy (calories) digesting food after early meals as compared to after dinner. Additional research shows that insulin and glucose increase at a greater rate following evening meals, even though insulin secretion is typically reduced at night. So if your stomach wakes up when you do, take that as a cue that breakfast is for you.
Mental and physical activity. Some studies suggest that eating breakfast can have short-term effects on memory, concentration, and reasoning and decision-making, particularly in children. This is particularly true for high-fat, low carb breakfasts. And fueling up early may help you feel energized and move better during the early hours of the day (though breakfast eaters also tend to consume more calories throughout the day). So if you're feeling sluggish or unfocused early in the day, adding or improving on breakfast may help you power up.
Time-restricted feeding (tRF). tRF is a variation of intermittent fasting (IF) in which food intake is restricted to certain hours of the day (usually 8-10 hours). Prolonged IF is meant to switch our energy source from food to stored fat by reducing the production of insulin (the storage hormone) and the availability of sugars to store. Studies show that IF may improve cognition, prevent onset of neurodegenerative diseases and improve insulin sensitivity. And tRF, or circadian rhythm fasting, may be a more sustainable and effective means to weight loss. However, unlike the effects of eating breakfast, practicing tRF by delaying breakfast requires adherence over a period of time to reap the benefits, particularly with respect to body composition.
What we eat. More important than when we eat is what we eat. We often associate morning meals with sugary cereals or baked goods. A mix of whole grains (e.g., oatmeal) or other unprocessed carbs (e.g., fruit), healthy fats (e.g., nuts), protein (e.g., eggs, yogurt) and fiber will provide an immediate boost in energy, keep you feeling full until lunch and let you focus on the tasks at hand. If you plan to postpone breakfast until you leave home (in a post-COVID world), pack it to go or make a plan for what to grab when hunger strikes.
If you're still not sure how to frame your morning, give yourself permission to experiment with when and how you break the fast. Then track your energy levels, cravings and productivity to learn what has worked and what has not. This awareness will be invaluable in helping you structure your first meal of the day.