One of the biggest nutrition myths is that you should never eat carbohydrates at night because they will supposedly be turned into fat. A related myth is that you should eat carbs in the morning so that your body can burn them off during the day.
Neither of these beliefs is true. They don’t reflect how your body actually works.
The good news, as you’ll see below, is that there are a number of great reasons to eat carbs at night—all of which can contribute to improved body composition and an all-around happier life.
Reason #1: Greater Relaxation/Better Mood.
Research shows that food can directly influence your brain neurotransmitter systems, which dramatically effect mood. One neurotransmitter in particular that influences how you feel is serotonin.
Serotonin is best known as the “feel good” neurotransmitter, improving mood and providing a sense of calm. When serotonin is elevated at night it enables restful sleep. It just so happens that eating carbs is necessary for the body to synthesize serotonin.
It works like this: the amino acid tryptophan is the precursor to serotonin and it is not taken up for conversion when other amino acids from a high-protein diet are present. However, when you eat carbs they trigger insulin, which reduces amino acid levels in the blood so that tryptophan can easily cross the blood brain barrier for conversion to serotonin.
Timing is a key point when it comes to using food to influence how you feel. We know from studies that the relationship between food and mood depends on at least two factors—the time of day and the macronutrient composition of the food. It’s also greatly affected by your individual dietary and genetic situation—for example, women and men may respond somewhat differently to various foods.
In the case of serotonin, when it is elevated in the morning or during the day, it can make people feel sleepy, calm, or even lethargic. Combine these effects with how higher carb foods can influence insulin and blood sugar, and many people find themselves unmotivated, sluggish, or foggy.
A solution is to favor higher protein foods in the morning and during the day because they provide amino acids that activate a cluster of energizing brain neurons called the hypocretin network. Then, enjoy higher carb foods at dinner or as a bedtime snack to help raise serotonin for a relaxing evening.
Reason #2: Improved Sleep.
There’s a second way that having carbs at night can help you sleep. In addition to raising serotonin, carbs help lower the stress hormone cortisol, which can inhibit sleep when it is elevated at night.
Your body follows a circadian rhythm by which hormone levels change over the course of the day. Cortisol is one of these hormones—it makes you feel alert when it is elevated in the morning to get you out of bed. Then, cortisol should drop over the course of the day, reaching low levels at bedtime to allow for sleep. But if you train or work late, or deal with “life” stress later in the day, cortisol can flood your system, keeping you anxious and awake.
Eating carbs can help reduce cortisol because they trigger a prolonged release of the hormone insulin, which is an antagonist to cortisol. High cortisol is one reason a lot of people crave high-carb “comfort” foods since their body is looking for a way to combat the physiological stress response and lower cortisol.
Which carbs should you eat at night?
Whole food, complex carbs such as starchy vegetables, fruit, beans, and boiled grains are good choices that will provide high-quality nutrition. Best results generally come from staying away from refined and processed carbs—everything from bread to crackers, cookies, ice cream, and so forth.
Reason #3: Better Use of Willpower.
Willpower has a shelf life. Studies show that it’s a limited resource that we can literally run out of over the course of the day.
And let’s face it, eating healthy and being mindful of portions requires some willpower. The reality is that for most of us, willpower is topped off in the morning, but we could use more flexibility with our eating at the end of the day. Timing your intake of macronutrients accordingly is one way to get better use of your willpower.
For example, higher carb foods tend to stimulate food intake, whereas protein is usually more satiating and leads to lower calorie intake. The solution is to plan daytime meals around protein (with healthy fat and vegetables) to keep blood sugar steady and minimize feelings of hunger. Saving higher carb foods for dinner means you don’t have to fight off carb cravings when your willpower is empty.
Reason #4: Greater Metabolic Flexibility.
Our bodies work best when they are metabolically flexible—that is, able to readily switch back and forth between burning carbs and fat. Metabolic flexibility is the ideal state because it allows you to avoid low energy levels if you haven’t just eaten.
When you eat the typical high-carb Western diet, you are repeatedly spiking insulin and raising your blood glucose to give yourself the energy needed to make it through the day. Many people develop insulin resistance from such a metabolic environment and their bodies lose the ability to readily burn fat.
Having a higher protein breakfast and saving carbs for later in the day is the perfect solution:
It means your body will maintain (or restore) it’s metabolic flexibility and be more likely to burn fat throughout the day. Your cells’ insulin sensitivity also improves so that when you do eat carbs, they will not be stored as fat but will be burned for energy or used to replenish glycogen in the muscles and liver.
Reason #5: Have More Energy In The Morning.
Back in the 1960s scientists wrote about the tranquilizing effects of food. This led to research showing that when women ate high-carb meals in the morning they felt sleepy, whereas when older subjects over age 40 ate high-carb meals at lunch following a high-carb breakfast, cognition was impaired in contrast to a high-protein meal.
In addition, when older subjects ate protein for breakfast, they experienced sensations of tension and anxiety, though cognition was better. Scientists hypothesized this was due to the fact that the neurons in the brain change as we age, making them more sensitive to some of the amino acids in protein-rich foods such as tyrosine. Tyrosine is used to synthesize the energizing catecholamine neurotransmitters, dopamine and norepinephrine.
The take away is that many people find they have more energy and better cognitive focus by favoring high-protein foods in the morning and getting their carbs at night. The nighttime carb intake appears to be key—people on low-carb diets often report trouble sleeping and may find themselves with chronically depleted muscle glycogen stores if they exercise regularly.
During activity, your muscles run on carbs that are stored within the muscle (called glycogen). Having carbs post-workout and in the evening is going to be much more effective for filling those glycogen stores so you are ready to go in the morning since glycogen storage takes time. This is why the most important meal to set you up for a workout is going to be the one you have the night before.
What about eating carbs during the day?
This depends on your individual activity levels, goals, and how carbs make you feel during the day.
If excessive stress is an issue for you, shunning all carbs during the day is not recommended. Try out a variety of whole food carbs to see which ones help you combat stress the best. Some people will get best results by eating low-glycemic veggies at meals, whereas others who tolerate carbs better will respond to higher glycemic grains and starches.
If you have to train in the afternoon or evening, experimentation is key. Some people, especially athletes or those doing hardcore, intense training will find that if they eat low-carb, higher protein all day, they have nothing left in the tank a quarter of the way through the workout. Therefore, eating some higher carb foods to refill glycogen stores at least 3 to 4 hours pre-workout is indicated.
On the other hand, if you’re training for fat loss, you may not have a problem going into a workout running on protein and healthy fat.
The ultimate take away is that it’s important to experiment. Don’t just follow the pack and always load up on carbs for breakfast if it’s not working for you.
Clearly, everyone responds differently to carbs, protein, and mixed meals based on everything from age and gender to metabolic health, dietary history, activity levels, cognitive requirement, and stress.