If the movie Gremlins taught us anything it is that we all know better than to feed a mogwai after midnight. Even the creatures themselves (or at the least the more intelligent specimens) seem to understand the wages of 3 am pizza: complete metamorphosis. Unfortunately, some dietary prescriptions purport similar fear in humans as to what will happen to our bodies if we consume carbohydrates beyond a specific time of day. Most commonly I have heard of cutting off carbohydrate intake after 8 pm. Nutrition myths, misunderstandings, and flat out inaccurate information tend to have a way to live on.
A couple of the biggest myths around carbohydrates are:
1. You should never eat carbohydrates at night because they will be turned into fat.
2. You should eat carbs in the morning so that your body can utilize and “burn” them off during the day.
Neither of these beliefs is true. They don’t reflect how your body works.
In fact, recent studies have shown promise that carbs at night are far more effective in terms of fat burning over limiting them to morning consumption (when total caloric intake is controlled). There are several reasons to eat carbs at night—all of which can contribute to improved body composition and an all-around happier life.
Research shows that food can directly influence your brain neurotransmitter systems, which dramatically effect mood. One neurotransmitter 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.
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. This is not too far different than mogwai’s body knowing when solar midnight occurs. Far more than a mere pattern for wakefulness and sleep, it affects a host of biological processes, including hormone production. 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, 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.
Improved Metabolic Flexibility
Our bodies work best when they are metabolically flexible—that is, able to readily switch back and forth between utilizing carbs and fat for fuel. 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. In this case, a controlled ketogenic diet may be of benefit to restore insulin sensitivity after which a gradual reintroduction of carbohydrates can be applied. Your body will restore its 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.
Prioritizing protein in the earlier part of the day and saving carbs for later at night can help to maintain metabolic flexibility.
Each person is different in their response and universal nutrition prescriptions do not apply. 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. 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. It is my recommendation to find out what works best for you, over following any one set of guidelines for carbohydrate consumption. The truth is, as with most all things related to nutrition, the answer as to what will work best for you is: it depends.
- Are you saying I shouldn’t eat 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.
- Training time and intensity are factors to consider: If you 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. And if you train EARLY in the morning, then I would consider your last meal before bedtime to be your pre-workout nutrition.
- The type of carbs chosen make a difference: 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.