Why Meal Timing May Be the Key to Metabolic Health

The adage "eat breakfast like a king, lunch like a prince, and dinner like a pauper " might be true. Some research suggests that eating most of your calories earlier in the day is the best bet for metabolic health.

So, does meal timing really matter? A whole field of study—scientifically known as chrono-nutrition—studies the relationship between meal timing, biological clocks, and health. Here's everything you need to know about meal timing and how to incorporate the key principles into your diet plan.

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Why Does Meal Timing Matter?

Our bodies operate on a 24-hour clock known as the circadian rhythm. You might be familiar with this term in the context of your sleep-wake cycle, but it also governs many other areas, including how efficiently we digest food.

A growing body of evidence shows that our metabolisms are more efficient in the morning. So instead of sitting down to cereal at breakfast and a steak and potatoes for dinner, research suggests we should eat a larger breakfast and smaller dinner instead. Eating late at night isn't "in line with the biological clock" and is associated with weight gain, type 2 diabetes, and cardiometabolic risk factors, according to a 2023 study. But our genes also play a significant part here.¹

The same study shows that people with certain gene variants are more susceptible to eating more, skipping breakfast, and sleeping less—all habits that increase the risk for weight gain and other metabolic issues. 

The Benefits of Eating More Earlier in the Day

Good news for those who wake up starving: Eating a big breakfast has benefits. Research shows that eating most of your carbs at the beginning of the day reduces the risk of developing diabetes and metabolic syndrome. 

A study published in 2022 in Obesity Reviews looked at data from 485 adults and found that people who ate most of their calories earlier in the day lost more weight and saw bigger improvements in blood sugar, cholesterol, and insulin sensitivity compared to those who ate later in the day.²

Why? Simply put, our optimal eating times are dictated by our circadian rhythms. Eating earlier in the day may support weight loss because it aligns better with our body’s natural circadian rhythms. Late meals can disrupt these rhythms, affecting metabolism and increasing the risk of weight gain and metabolic diseases. Earlier eating also boosts calorie burning and stabilizes blood sugar levels, reflecting how our bodies associate evenings (i.e., darkness) with sleep rather than eating.

You know when you eat a huge dinner, indulge in dessert, and then wake up feeling ravenous the next day? It's not all in your head. A study in the journal Cell Metabolism reveals that eating late at night can mess with your hormones and cause you to feel hungrier.  It was a small study done on 16 people, but it showed that those who ate late at night had altered appetite-regulating hormones that promote fat storage; plus, they burned fewer calories—a recipe for a higher risk for obesity.³

We did our own research here at Signos and analyzed data from 926 members on the trends behind their glucose spikes. We found that the people who had their last glucose spike (meaning they did something that caused their glucose to rise, like eating a meal) before 5:40 pm lost three times more weight than those who had a glucose spike after 8:40 pm. That shows that avoiding large spikes later in the evening can possibly help with weight loss. If you're a nighttime eater, you can help prevent spikes with a dinner with higher protein and fat content and lower in carbs.

Does Intermittent Fasting Play A Role?

Some say intermittent fasting (IF), especially time-restricted feeding (TRF), has become a popular weight loss strategy—even biohacking. Eating windows like the 16:8 diet, where food intake is limited to 8 hours a day (with a 16-hour fasting period), can encourage intentional meal timing that aligns with the body’s natural rhythms. However, the timing of these eating periods significantly affects the results.

A study on early time-restricted feeding (a 6-hour eating window ending by 3 p.m.) showed that even without significant weight loss, participants improved their insulin sensitivity, blood pressure, inflammation, oxidative stress, and appetite compared to those on a 12-hour eating schedule. This highlights the added metabolic benefits of eating earlier in the day.⁴

<div class="pro-tip"><strong>Also Read: </strong><a href=meal-timing-with-thomas-delauer>How Impactful Is Meal Timing? Thomas Delauer Speaks Up</a></a>.</div>

How to Put Meal Timing Into Practice

OK, so you're convinced to front-load your calories and stick to a smaller supper. Easier said than done, right? Here are some practical tips to help you put this practice into a lifestyle:

• Start With a Protein-Packed Breakfast: We tend to get most of our daily protein at dinner, but to support our metabolism better, we should switch that. Aim to get at least 25 grams (30 grams, ideally) of protein at breakfast. Foods like egg whites, Greek yogurt, or a smoothie with protein powder can help keep you full and energized.
• Eat More Earlier in the Day: Try to front-load your calories with a bigger breakfast and lunch and have a lighter dinner. The same goes if you're on a calorie-restricted diet — portion more of your daily calories for breakfast.
• Give Yourself a Window: Aim to finish eating at least 2 to 3 hours before bed to support better sleep and metabolism.
• Time Meals Around Workouts: If you have a long run or weight-lifting session planned, make sure to have a balanced snack rich in carbs to help fuel your workout. If your goal is to gain muscle, ensure you're hitting your protein goal while focusing on meal timing.
• Avoid Late-Night Snacking: Going to bed hungry is never the answer, so if you find yourself peckish come p.m., go for something high in protein and low in carbs to help prevent that blood glucose spike. Try meat jerky, canned tuna with avocado, cottage cheese with berries, or Greek yogurt.
• Stay Consistent But Flexible: Aim to stick to your meal times, but don’t stress over periodic changes or special occasions. Always try to pay attention to how different meal times make you feel. That way, you can adjust based on what works for your energy and hunger levels.
• Stay Hydrated: Drinking enough water throughout the day can help with hunger and digestion.

Frequently Asked Questions

What Is the Ideal Time to Eat a Meal?

The study of chrono-nutrition, or how meal timing around our biological clocks affects our health, suggests that breakfast should be the day's largest meal. It's centered around the idea that our body's circadian rhythm also dictates our metabolism's efficiency. Eating earlier in the day boosts calorie burning and stabilizes blood sugar levels because our bodies associate nighttime with sleep rather than eating.

What Is the Meaning of Meal Timing?

Meal timing refers to when, i.e., the time of day, you choose to eat your meals. The study of chrono-nutrition looks at how timing our meals around our biological clocks affects our metabolic health.

<div class="pro-tip"><strong>Learn More: </strong><a href=how-to-make-a-meal-plan>How to Make a Meal Plan? Meal Planning 101</a>.</div>