Is There a Best Time to Eat Carbs?

Carbs are one of the three macronutrients, alongside fat and protein.

They’re your body’s preferred source of fuel and provide 4 calories per gram. Most carbs are broken down into glucose, a type of sugar that can be easily used for energy (2).

There are two main types of dietary carbs (3):

• Simple carbs. These contain one or two sugar molecules. Foods that are high in simple carbs include sugar, fruits, fruit juice, honey, and milk.
• Complex carbs. These have three or more sugar molecules. Foods that are high in complex carbs include oats, brown rice, quinoa, and sweet potatoes.

Generally speaking, complex carbs are healthier, as they pack more nutrients and fiber and take longer to digest, making them a more filling option (3).

That said, simple carbs can be a better source of fuel in some instances, especially if you have a workout that starts within an hour. That’s because your body breaks them down and absorbs them more quickly (4).

Though carbs are an important source of fuel, eating too many can lead to weight gain. If you eat more carbs than your body needs, they’re stored as fat for later use.

Summary

The two main types of carbs are simple and complex carbs. While complex carbs are generally the healthier option, simple carbs can be useful in situations in which you need energy quickly, such as within an hour before a workout.

You may wonder whether timing matters when it comes to eating carbs.

The following section reviews the research on the best time to eat carbs for different goals.

To lose weight

When it comes to fat loss, research on the best time to eat carbs is inconsistent.

In one 6-month study, 78 obese adults were asked to follow a low-calorie diet that involved eating carbs either only at dinner or at every meal. The dinner-only group lost more total weight and body fat and felt fuller than those who ate carbs at every meal (5).

Conversely, another study in 58 obese men following a low-calorie diet with either more carbs at lunch or dinner found that both diets were similarly effective for fat loss (6).

Meanwhile, a recent study observed that your body is better at burning carbs in the morning and fat in the evening, meaning that carbs should be consumed earlier in the day for optimal fat burning (7).

Also, several studies indicate that weight gain tends to occur with eating more calories later in the day, so larger, carb-rich meals in the evening may hinder fat loss (8, 9, 10).

Due to these mixed results, it’s unclear whether there’s a best time to eat carbs for fat loss.

Additionally, your total carb intake is likely more important than timing, as eating too many carbs or calories from other nutrients can hinder weight loss (11).

Aim to choose more fiber-rich, complex carbs like oats and quinoa over refined carbs like white bread, white pasta, and pastries, as the former are generally more filling.

To build muscle

Carbs are an important source of calories for people looking to build muscle mass. However, only a few studies have looked into timing carb intake for this purpose.

Some studies find that consuming carbs along with protein within a few hours after a workout may help increase protein synthesis, which is the process by which your body builds muscle (12, 13).

Yet, other studies indicate that eating protein on its own post-workout is just as effective at stimulating protein synthesis as consuming protein along with carbs (14, 15, 16, 17).

That said, when resistance training, your body relies significantly on carbs as a source of fuel, so a carb-rich pre-workout meal or snack may help you perform better in the gym (1).

In addition, carbs have a protein-sparing effect, which means that your body prefers to use carbs for energy instead of proteins. As a result, it can use protein for other purposes, such as building muscle, when your carb intake is higher (18).

Moreover, eating carbs after a workout may slow the breakdown of protein that occurs post-workout, which may aid muscle growth (19).

Still, for most people, eating adequate amounts of healthy complex carbs throughout the day is more important for building muscle than timing.

For athletic performance and recovery

Athletes and people who exercise intensely can benefit from timing their carb intake.

Research shows that eating carbs before and after a workout can help athletes perform longer and recover more quickly. It also reduces muscle damage and soreness (1).

That’s because exercising for long periods can deplete your muscle glycogen stores (the storage form of carbs), which are your body’s main source of fuel.

Consuming carbs at least 3–4 hours before a workout can help athletes exercise for prolonged periods, while consuming them within 30 minutes to 4 hours after a workout can help restore your glycogen stores (1, 20).

What’s more, having protein alongside a source of carbs after an intense workout can further help your body replenish its glycogen stores, all while aiding muscle repair (1).

While athletes and people who exercise multiple times per day can benefit from timing carb intake around workouts, research indicates that it’s less important for the average person.

For the ketogenic diet

The ketogenic, or keto, diet is a very-low-carb, high-fat, moderate-protein diet, often used to lose weight.

It typically involves restricting carb intake to less than 50 grams per day to reach and maintain ketosis, a metabolic state in which your body burns fat for fuel instead of carbs (21).

Currently, evidence to suggest that timing your carb intake to aid weight loss on a keto diet is lacking.

However, if you’re an active person, timing your carb intake around your workouts may improve your performance. This is known as a targeted ketogenic diet (22).

Furthermore, if you experience insomnia while on a ketogenic diet, eating carbs closer to bedtime may help you relax and fall asleep faster, according to some research (23, 24).

Summary

Eating carbs at certain times does not appear to improve weight loss on low-calorie or ketogenic diets. However, timing carb intake around workouts can benefit athletes and people who exercise heavily.

Carbs can play an important role in many health and fitness goals.

Athletes and people who exercise multiple times a day may improve their performance by eating carbs before a workout and speed up recovery by eating them afterward.

Still, for the average person, timing seems to be less important than choosing high-quality, complex carbs and watching your total calorie intake.