A dietitian’s advice on meal timing
When you eat can be nearly as important for your metabolic health as what you eat. Here’s what one nutritionist tells her clients about optimal meal timing.
One of the most common questions I get as a registered dietitian nutritionist after what to eat is when to eat. Is breakfast the most important meal of the day? Should I eat before or after my workout? Is late-night snacking bad for me? Optimal meal timing for metabolic health depends on a variety of factors. When I develop nutrition plans for my clients, I consider not only the quality and composition of their meals and snacks but also their timing.
Before diving too deeply into the science, I want to emphasize that food should support not only physical health but also mental and emotional well-being. The research on meal timing can be conflicting, so finding an approach that works for you is essential. For instance, while intermittent fasting may help with short-term weight loss, if it leads to missing out on dinner with your family or struggling to focus on morning tasks because you’re hungry, it might not be the right fit. Ultimately, the most sustainable strategy is finding an eating pattern that controls excessive hunger, stabilizes energy levels, and allows for balanced, nutritious meals.
With that in mind, let’s dive in.
5 Common questions about food timing
Is intermittent fasting right for me?
Intermittent fasting (IF) is a type of fasting that limits intake for a specific amount of time. One of the most common approaches is time-restricted feeding, in which a person restricts their “eating window” to a certain number of hours. For example, they may choose an 8-hour eating window between 11 am and 7 pm, leaving a 16-hour fasting period. IF has been associated with various metabolic health benefits, such as weight loss, improved metabolic flexibility, and increased insulin sensitivity. However, the jury is still out about exactly how long of a fasting window is needed to achieve these effects.
When helping my clients decide whether IF is right for them, I take into account several factors, including gender, hormonal status, weight goals, and lifestyle. I don’t recommend fasting to anyone who is underweight, susceptible to disordered eating behavior, elderly, or trying to conceive. Women can have different responses to IF than men due to hormonal fluctuations and may experience negative side effects such as disrupted estrogen, cortisol, and thyroid hormones, increased hunger, inflammation, and fatigue. They can ameliorate these effects by avoiding extended fasts in the second half of their cycle (also a good time to increase their intake of healthy carbs) and when sleep-deprived or overly stressed.
Is it bad to eat late at night?
I advise my clients to stop eating 2-3 hours before bed whenever possible to support sleep and metabolic health. Eating too close to bedtime can disrupt blood sugar balance, hunger hormones, and fat metabolism. It can also lead to acid reflux and gastric distress. Of course, life happens, and sometimes eating late at night is unavoidable. In this case, I recommend having a light meal or snack such as yogurt or cottage cheese with berries or veggie sticks, hummus and crackers, or a low-carb sandwich roll-up. Insulin sensitivity is lower in the evening than in the morning, so avoiding anything too carb-heavy before bed is best. Avoid anything spicy, acidic, caffeinated, or hard to digest, as these can disturb sleep.
Is it true that breakfast is the most important meal of the day?
Shifting most caloric intake to earlier in the day can benefit metabolic health by improving appetite control, blood sugar balance, and nutrient metabolism. However, simply adding a morning meal doesn’t necessarily lead to reduced appetite, a higher resting metabolic rate, or weight loss, suggesting that the benefits may be better attributed to curbing late-night eating.
When I help my clients think about breakfast, I encourage them to consider how late they typically eat dinner, their usual morning hunger level, and their schedule. If you’re in the habit of eating a large meal at 9 pm and starting your day off with a croissant at 7 am because it’s the fastest thing you can grab, you’re probably better off waiting until you have time to sit down for a healthy meal. But leaving three hours between dinner and bedtime and eating a high-protein breakfast is ideal. Research suggests that 30 grams of high-quality protein per meal is vital for muscle protein synthesis, the process in which your body builds and repairs muscle tissue.
I have my first meal of the day around 9 am and emphasize protein, fiber, and healthy fats. My go-to’s are a green smoothie, breakfast burrito, several egg bites, or protein chia seed pudding.
What’s better, two large meals or small, frequent meals throughout the day?
The debate about whether to eat a few large or several small meals is ongoing, with research showing mixed results. A recent meta-analysis examining the impact of meal frequency on body weight and metabolic health biomarkers, such as lipids and insulin, found no significant difference between high and low eating frequencies.
Some studies suggest that eating smaller, more frequent meals can help stabilize blood sugar levels and promote consistent energy levels throughout the day, which can help with cravings and weight management. Eating small, frequent meals may also help ensure adequate caloric intake, particularly for older adults, people with gastrointestinal issues that cause early satiety, or those suffering from diseases such as cancer that affect appetite.
On the other hand, consuming fewer large meals has been associated with a higher thermic effect of food—the increase in your metabolic rate after you eat—compared to small, frequent meals. Some also argue that in today’s calorically abundant environment, eating less frequently helps control excessive intake and combat weight gain.
Ultimately, your optimal meal frequency depends on your preferences, schedule, and health goals. I encourage my clients to follow an eating schedule that allows them to consume balanced, nutritious meals, provides stable energy levels, and prevents disruptive hunger.
How should I time my meals and snacks with exercise?
As with many other areas of nutrition, it depends. Recent evidence suggests that fasted exercise results in more fat burning, but eating carbs before endurance training (such as a marathon or long-distance cycling) can improve performance. More information is needed to determine the effects of a protein-rich breakfast on fat oxidation during exercise.
As with IF, recommendations may differ for women. Exercise physiologist and nutrition scientist Dr. Stacy Sims recommends that women ingest some carbohydrates and about 15 grams of protein before training to counteract the stress that increased cortisol and fasted exercise can have on the body (she does this by putting almond milk and protein powder in her morning espresso). She also advises that women in their reproductive years eat a meal with approximately 35 grams of high-quality protein within 45 minutes after training to facilitate recovery.
I don’t coach athletes; most of my clients are doing moderate-intensity workouts under an hour, so I advise them to consider their goals and listen to their bodies. Key signals to listen for include energy levels, digestion, and overall comfort during and after exercise. I like to work out first thing in the morning. I can’t tolerate too much food beforehand, so I might have half a banana with almond butter or drink my coffee with cashew milk for protein and healthy fats. If you exercise after work, I suggest eating a balanced meal several hours prior. I also recommend that my clients get in the habit of walking after meals whenever possible, as this can help keep your blood sugar stable by making your muscle cells more efficient at processing glucose.
A note on nutrition research
You probably noticed how many times I said, “It depends.” I am an evidence-based practitioner, but I emphasize personalization in my recommendations because everyone is different, and there are few universal lessons from research. That’s because conducting widely applicable nutrition research is challenging for several reasons. Studies often rely on self-reported information, which can be inaccurate due to memory errors or intentional misreporting (no one’s too excited about owning up to that late-night donut binge). Also, lifestyle factors like healthy eating and exercise are usually connected, making it hard to isolate the specific effects of each variable. Collecting accurate nutrition data in real-world settings is complicated, as subjects must make a deliberate effort to adjust their lifestyle to the study parameters and undergo long-term monitoring. These challenges suggest we should take broad recommendations with a grain of salt and underscore the importance of observing our bodies through bio-observability. I provide my clients with the latest research and help them use it with their biodata to make informed decisions about their health.
Conclusion
By being intentional about when you eat, you can dramatically influence your metabolic health. Avoiding late-night eating and finding a way to control excessive hunger, stabilize energy levels, and allow for balanced, nutritious meals are powerful strategies. It’s also essential to balance these goals with the enjoyment and social connection that food can bring.
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