Many strategies allow us to approach nutrition in a way that works. When it comes to manipulating carbohydrates, you can change one or more of the following: Amount, timing, and quality. Carb backloading, in particular, focuses on timing or when to eat your carbs.
Carb backloading is popular in fitness and bodybuilding communities as a way of losing weight while increasing muscle mass. For those who are considering it, this guide discusses its effectiveness, pros and cons, and how to safely implement it.
Developed by John Kiefer, an exercise and nutrition expert, carb backloading (or CBL) involves eating carbs later in the day instead of throughout the day. While carb backloading is more common in men who do resistance training — for the purpose of gaining muscle without gaining body fat — women who love lifting may use it too.
With that being said, carb backloading is best paired with a workout regimen, particularly strength training. It appeals mostly to individuals who schedule their workouts in the late afternoon or early evening.
The general rule is to eat most of your carbs during the evening after working out. You can eat these carbs until bedtime (around an hour prior to sleep). As for breakfast and lunch, limit carbs to a total of 30 grams only.
Here’s an example:
Let’s say your workout days are Mondays, Wednesdays, and Fridays. During these days, you eat just 30 grams of carbs until 5 p.m. This means your breakfast and lunch would focus mostly on protein and fats, such as eggs, steak, chicken, and a small piece of fresh fruit.
After you lift weights in the late afternoon or early evening, you increase your carb intake from a variety of sources.
Some people mention that the best carbs to eat are complex carbs, such as sweet potato and quinoa to prevent blood sugar spikes, while others claim that simple carbs like white bread and pasta are allowed.
As long as carb backloading is properly done, a person will be able to improve their fat-burning potential. Carb backloading leverages the hormone insulin, which is released when glucose is present (*).
Given that our bodies are more insulin-sensitive during the day, which allows glucose to be stored in our fat and muscle cells — carb backloading takes this into account, and therefore, advises carb restriction during the day (*)(*).
Since you’re going to exercise in the evening, and exercise boosts insulin sensitivity, the glucose from carb-rich foods enters your muscles (*).
The result is that you lose weight (by limiting carbs in the morning and at lunchtime) and build muscle (by lifting weights in the evening, followed by eating carbs, which now enter your muscles).
Besides weight loss and muscle growth, here are reasons to try carb backloading:
- It may stimulate ketosis by limiting carbs during the day, which can enhance your focus and help you experience stable energy (*).
- It may help you sleep better at night by increasing tryptophan uptake in the brain (*).
- It’s a less restrictive approach than the keto diet, which limits your carbs throughout the day.
- The increase in carbs (whole food carbs), especially when combined with protein, may reduce muscle soreness post-workout (*).
- Protein and healthy fats, which are your primary focus during the day, help with many processes ranging from cellular repair to vitamin absorption and hormone production.
- It may help reduce cravings since you’re allowed to eat more carbs at night.
Carb backloading may or may not be better than other approaches for losing weight and building muscle at the same time. If you’re looking for research, you’ll find limited data. However, there are two commonly cited studies suggesting that carb backloading works.
In one study, female subjects ate most of their calories in the morning, while the other group consumed most of their calories in the evening. The results? Those who ate the bulk of their calories later in the day lost more weight while preserving lean muscle (*).
In another study, police officers underwent a low-calorie diet for 6 months where they ate carbs mostly at dinner time. Based on the results, this strategy led to reduced body fat, less hunger, and better fasting blood glucose. The study suggested that it appears to offer more benefits for individuals with obesity than a conventional weight loss diet (*).
The carb backloading protocol is straightforward: Restrict carbs to as low as 30 grams during the day. Eat more carbs in the evening after your workout session, which involves resistance training or strength training. As for the grams of carbs in the evening, there is no definitive rule — although some individuals who carb backload consume 1 gram of carb per pound of lean body mass.
The best meal plan for carb backloading includes ample amounts of healthy fats and protein, as well as whole-food carbs. Avoiding sugar-laden foods like donuts, pastries, and other traditional desserts will help to increase your chances of success on this diet strategy.
Here’s a sample menu of what you can eat as part of a carb backloading schedule:
- Breakfast: whole eggs (scrambled or boiled)
- Lunch: Shrimp stir-fry with cauliflower rice
- Dinner: Sweet and sour chicken with brown rice
- After-dinner snack: Sweet potatoes, bananas, or yogurt (with no added sugar)
To get the best possible outcomes while carb backloading, adhere to the rules. More importantly, track your body composition over time to know your body fat and muscle percentages. That way, you’ll be able to tell if carb backloading is working to your advantage.
Follow these carb backloading safety and success tips:
- Decide if an evening strength training workout suits your lifestyle. Otherwise, train in the morning and don’t do carb backloading.
- Focus on whole foods to meet your protein, fat, and carb needs. Avoid sugar and highly processed carbs.
- Since you’re limiting carbs during the day, try to sneak more protein and fats from a variety of sources.
- If you decide to eat carbs before bed, avoid those that contain caffeine and are spicy.
- Consult with your healthcare provider first if you have blood sugar issues — i.e., you’re diagnosed with diabetes, which causes hypoglycemia and hyperglycemia.
Carb backloading is unlikely to cause negative effects in people who are healthy. However, caution should be exercised for those with a medical condition involving insulin resistance, such as diabetes and polycystic ovary syndrome (PCOS). This is because eating too many carbs can make your glucose levels soar and worsen your condition (*).
Other people who should avoid carb backloading include pregnant women and those who struggle with an eating disorder.
Learn more about carb backloading by checking out some popular questions and answers on the topic:
What types of carbohydrates are recommended for carb backloading?
Complex carbohydrates, such as whole grains, quinoa, sweet potatoes, bananas, blueberries, and strawberries, are the best options for carb backloading. Complex carbs have fiber in them and digest more slowly. They also support weight loss.
How long does it take to see results with carb backloading?
Losing fat and gaining muscle at the same time (also known as body recomposition) using carb backloading takes time. As for how soon you can see results, you may be able to notice changes after 2-3 months — although results will depend on your consistency, strength training routine, sleep quality, and whether you’re hitting your protein goals.
Can I combine carb backloading with other dietary approaches?
It is possible to incorporate carb backloading into or use it together with another diet, such as a vegetarian diet, gluten-free diet, paleo diet, targeted keto diet, or cyclical keto diet. You may have to tweak your carb sources while going a carb backload depending on what your diet allows and doesn’t allow.
Should I track macros and calories on carb backloading?
There is no strict requirement to count calories and macronutrients while carb backloading. However, you would be better off counting protein during the day and in the evening. Keep in mind that protein is so important for growing muscle and shedding pounds.
Is carb backloading a long-term sustainable approach?
If you have tried following a low or very low-carb diet (such as the keto diet), you would understand that such diet can be challenging. In comparison with keto, carb backloading appears to be sustainable if your main goal is body recomposition. Like other diet strategies, the longer you stay on a carb backloading approach, the easier it becomes.
Proponents of carb backloading may claim that it helps boost muscle mass and drop body fat, but you must remember to follow the rules — such as eating only 30 grams of carbs during the day (while prioritizing fat and protein) and eating more carbs at night (while making sure these are complex carbs).
Since research on carb backloading is limited, we recommend closely tracking your results to see if it’s the best strategy for your goals.
NIH study shows how insulin stimulates fat cells to take in glucose. National Institutes of Health (NIH). https://www.nih.gov/news-events/news-releases/nih-study-shows-how-insulin-stimulates-fat-cells-take-glucose. Published October 2, 2015.
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