Obesity and being overweight might have their own effects on health, but so do being underweight. Lack of appetite, low self-esteem, and skinny body structure, I get it all.
I’ve been a hard-gainer myself, and being born with a fast metabolism sure has some cons apart from a few perks. In this article, I’ll discuss everything related to your question on how to gain weight with a fast metabolism, categorized into three segments or pillars of a muscle building and weight gain routine: Nutrition, Training and Rest.
If you’re reading this article, chances are that you’re already tried putting on weight by eating more, working out with heavy weights and doing everything that your gym trainer told you, but still aren’t seeing the results.
The good news is that since you’ve already embarked on the journey of transforming your body, it’s only a matter of consistency and dedication and the right knowledge that will help you put on healthy weight.
The dynamics of gaining weight with a fast metabolism are simple, you need to consume more calories than your body burns in a day. However, a high metabolism, busy schedule and unavailability of time to track calories make it all difficult for you to see results.
This is why this article covers each aspect of gaining weight including the right diet, foods that help you gain weight, the best weight gain supplement list and the benefits of working out in the gym. But before we dive into these topics, let’s see why you should be already working on putting on weight.
Consequences of Being Underweight
While obesity ranks as one of the major health concerns around the world, being underweight is not better.
According to this study, being underweight is associated with a 100% greater risk of early death in women and 140% in men. Being underweight also makes you at a higher risk of getting infections and may also impair your immune functions. Osteoporosis and fractures are also some other health concerns related to people who are underweight.
All of the health concerns mentioned above, combined with the low confidence and self-esteem, it makes it extremely essential for you to put on some healthy weight. Don’t worry, in this article, I’ll specifically talk about how to gain weight if you have a fast metabolism.
Why can’t I gain weight naturally?
There could be multiple reasons why you are not seeing any results and putting on weight. Keeping the medical conditions aside, the most common reason is not consuming enough calories.
Most hard-gainers, including me, claim that they eat more than an average person and still not gain weight. While for a specific meal at a particular time of the day this might be true, your overall consumption is still lesser than what your body burns. At max, you’re just consuming enough calories to maintain your current weight.
Don’t believe me? Try tracking your calories for a period of time, and you’ll see that the overall calorie consumption equates to the number of calories you need to maintain your current weight.
The second common reason for not seeing results could be your metabolism. Just like some people put on weight easily, your metabolism may need to you consume more calories than others in order to see results.
Another common reason is your activity levels. You may think you’re eating enough, but due to high activity levels or physical endurance, you might be burning a whole lot of calories.
The good news is, no matter what your reasons are, you can still gain healthy weight, irrespective of your genetics, metabolism or appetite. The only thing you need to know is that every human body is different, and what works for others may not work for you. This way, you’ll decide the right amount of calories for your body, given your activity levels and metabolism. Read more to find out some great tips on how to gain weight with a fast metabolism.
Quick Weight Gain Tips
Before we dive into the detailed three sections of helping you gain weight fast and build muscle, let’s quickly go through the overall points you need to remember. Here are some of the best ways to help you gain weight with a fast metabolism:
- Eat more calories.
- Eat foods rich in calories.
- Increase your meals and meal frequency.
- Eat more carbohydrates and proteins.
- Track your calories.
- Consider taking weight gain supplements.
- Focus on compound movements.
- Lift heavy weights.
- Get plenty of sleep.
- Stay focused.
Above all, make sure you focus more on the quality first, in both nutrition and rest. The quickest way to do this is by first including high-quality calorie-dense foods in your diet, and gradually increasing their portions.
Eat a Calorie Surplus:
This should be your foremost priority. In simple words, your body needs a specific number of calories in a day to perform day to day activities, both for men and women. When your overall calorie consumption and expenditure is at balance, you maintain your current weight. On the other hand, when you eat more calories than you burn in a day for a specific period, you start to gain weight.
As a starting point, start by calculating the number of calories you need in a day to maintain your current weight by using the Daily Calorie Calculator here: https://www.gainingtactics.com/daily-calorie-calculator/
Once you have this number, an ideal surplus would be somewhere between 300-500 calories. This will ensure that the weight you gain comes most from muscle, avoiding unnecessary fat.
An important thing to note here is that it is very easy to consume extra calories while gulping down pizzas and coke. While you will certainly gain weight fast with this, most of it would be from fat. This will do more harm than good in the future, and you should avoid this at all costs. Keep a high percentage of your calories from high-quality whole foods, and include cheat meals here and there to keep yourself motivated.
Focus on Calorie Dense Foods
An extension to the previous point, make sure that most of the calories you consume come from healthy whole foods that are rich in macronutrients. A good starting point would be to ensure that 80-90% of your calories come from clean whole foods, and the rest 10-20% could be from foods that you like.
Apart from junk food and sodas, you might also want to minimize the consumption of foods that are filling but do not help you reach your caloric requirements. These are foods that have high water content like cucumbers and some green vegetables. While these foods work great for your body and help you with the right micro-nutrients, you’ll have to balance out the diet by keeping the ones that are low in calories to a minimum.
Some of the best foods that will help you reach your goal of putting on healthy weight are the ones with high nutrition profiles and high in calories.
Don’t worry, I’ve already researched on all of this and listed some of the best foods you can include in your diet for gaining weight. In case you wish to check out, here’s a list of some of the best weight gain foods.
Focus More on Protein-Rich Foods
Out of the three macro-nutrients namely: Protein, Carbohydrates and Fats, Protein is the most essential one when it comes to repairing and building muscles. This does not mean that you completely minimize carbs and fats, but this means that you prioritize protein consumption.
A high protein diet is advisable not just to the people who’re looking to build muscle, but for anyone who indulges in any form of physical activity. This is because protein, which is known as the building block of muscles, is known to supply essential amino acids to the muscle tissues that were damaged during the physical activity. These tissues, when fed with enough nutrients and given time to recover, grow stronger than before.
Protein also improves body composition and helps you put on lean muscle. With all these reasons, maintaining a high protein diet and consistently including protein in every meal should be your priority for gaining healthy weight.
Related: In case you were wondering, taking a whey protein supplement does assist in helping you reach your protein requirements. Here’s a complete article on how you can use whey protein to gain weight.
Don’t Forget your Carbohydrates and Fats
No matter what you read on the internet or in the free gym articles, do not excessively cut down on carbs and fats just because someone said they were bad for you. Carbs and Fats are equally beneficial for your body and would equally assist you in putting on healthy weight like protein. Both have their own benefits for your body.
Carbs, for example, is the macronutrient that helps you recover from workouts and makes sure that you feel energized to perform the physical activity. During a physical activity session, your body uses up glycogen in order to fuel the workout. The carbohydrates consumed after the workout make sure that these glycogen levels are replaced, and you recover well from the physical activity.
Another reason why you should not cut down on carbs is that they are the source of energy for your body during a workout. In case your body does not have enough carbohydrates, it might feed on your muscle protein to fuel the workout and replenish muscle glycogen following the workout.
Our body has the ability to convert fats and protein into glucose. If not provided externally through diet or supplements, our bodies start to utilize protein and fats for energy and to maintain the levels of glucose.
There are three types of Carbohydrates that you need to know, namely: Complex Carbohydrates, Simple Carbohydrates, and Fiber. Complex carbohydrates are slow-acting carbs and provide vitamins and minerals that are important for our health. Some of the foods rich in complex carbs include bread, rice, and vegetables. These are the type of foods that you wish to focus on if you’re looking to put on healthy weight.
Simple carbs, also called as sugars, are fast-digesting carbs that do not provide vitamins and minerals to the body. Since they are fast-digesting, they are also referred to as empty calories and do not provide much nutritional values. Common examples include raw sugars, sodas, packaged cookies, etc. This is the category of carbs that you need to avoid or limit to small amounts.
Lastly, fiber is the indigestible part of plant foods that passes through your intestines and isn’t digested. Fiber is known to contribute to digestive health and improve cholesterol levels. Some of the best food sources of fiber include fruits and vegetables, whole grains and beans. Fiber should be an essential part of your diet.
Fats, on the other hand, are classified into Saturated, Unsaturated and Trans Fats based on their certain properties. The only thing you need to remember here is that fats are essential for our bodies and help in providing energy and supporting cell growth.
Since each gram of fat contains 9 calories(highest among all macro-nutrients), the right amount of fats will help you reach your caloric goals faster and promote better health. Some examples of healthy fats include avocados, dried fruits, nuts, whole eggs, and fish.
The best way to reach and maintain your calorie surplus requirement is to eat smaller meals frequently, both for men and women.
For instance, you calculated your daily calorie needs for gaining 1 pound of weight in a week, and it came out to be 3000kcal/day. This requirement can either be fulfilled by eating three meals a day, each of 1000kcal a meal, or by eating six smaller meals of 500kcal each.
The reason why eating 1000kcal is not advisable is because being a hard-gainer, you would not have the appetite to eat this much for a very long time. Secondly, eating smaller meals is known to boost metabolism, and is an easier way to meet your caloric requirement on a daily basis.
On a similar note, the reason why most people who claim they eat a lot do not gain weight is that body composition and weight management are slow processes. Eating a high-calorie meal once a day and then going through the rest of the day without eating balances the equation, and you’re ultimately eating only the amount of calories needed to maintain your current weight.
The best way to meet the caloric requirement, that I personally follow, is waking up early in the morning, and distributing the meals evenly into 7-8 small meals, and eating every 2-3 hours. This includes 3-4 large meals, and 2-3 snacks or short meals in between.
Remember that in order to gain healthy weight, you will have to do this consistently until you see results and achieve your fitness goals. Since every body is different and reacts differently to what is put in it, you need to figure out the best for your body.
For some, eating 3-4 large 1000kcal meals throughout the day might work better compared to eating smaller meals. This is the case with people who have busy schedules, and do not have enough time to eat every 2 hours.
For others, eating small meals frequently might do the trick. Ultimately, you need to work on different approaches and see which ones work the best for your body and choose the one that you can consistently follow despite your busy schedule.
Get Creative with Foods Items
This is one of the most underrated points that I consider while putting on weight. The idea here is to get creative and mix and match foods that add calories to your current meals. Items like spices, sauces, yogurt, olive or avocado oil, and nuts are some of the best examples of foods that you can add in order to increase the calorie content. These are just a few to name.
A great example of getting creative and how I like to increase my calorie intake is by including 1-2 servings of thick mass gainer shake into my routine. While a normal weight gainer shake only contains milk/water and mass gainer, I like to get creative by using Whey Protein Isolate( cheaper as compared to a mass gainer) mixed with Whole Fat Milk and blend them together with items such as peanut butter, quick oats, a flavored syrup( just for taste) and some fruits such as a banana. This shake is a whole lot cheaper than mass gainers and gives me more healthy calories at the same time.
You could try adding your own food items like Vanilla ice cream, nuts and dried fruits, seeds like flax-seeds, Greek yogurt or even berries. The smoothie should give you a whole lot of calories, while being high in nutrition at the same time. Now that you know, it’s time to get creative with your food!
Related: Just like in the case of food, you might get confused between different supplements, and which one to choose for gaining weight fast. I’ve recently compared Mass Gainer vs Whey Protein Supplements, and it covers everything from each of their benefits to side effects. Go check the article out!
Consider taking Weight Gainer Supplements
While I’ve always focused on the importance of making your own mass gainer shake at home, there’s no denying that if you do have a budget for mass gainers, they certainly help.
Not sure about the right supplements for gaining healthy weight? Let us help you out:
Mass or weight gainers are supplements that are not only high in protein and carbohydrates, but they also make sure that you reach your caloric goals by providing you the calories in abundance. They’re also high in sugars, which might make you gain fat, but if you’re someone who’s struggling to put on weight and does not have enough time to eat frequent meals, investing in a good mass gainer is worth taking the decision.
Alternatively, you could also invest in a natural testosterone booster, that helps you repair muscles faster and helps you gain weight faster.
This brings us to an important point. First, invest in a mass gainer only if you have tried consuming cheap whole foods and still aren’t able to meet the caloric requirement, or if you’re someone with a very busy schedule and do not have much time to prepare and consume high-calorie meals frequently. Taking a mass gainer does not mean that you can give up on the whole foods diet, and solely depending on the supplements equals wasting your money.
Supplements, be it mass gainer or a whey protein, only work if you have a proper nutrition plan in place. What this means here is your priority should always be to get most of your calories from high-quality whole foods mentioned in the list above. In case you find any gaps in your current diet and the required calorie intake, it’s time that you incorporate a mass gainer.
The market has a variety of mass gainers available, and all of them have their own pros and cons. Some might offer more protein per serving, while some may offer double the calories compared to others. The best way to decide is to check the nutrition label of different mass gainers that you wish to purchase, and then matching it with your requirements.
I’ve done most of the research for you, and you can read more about some of the best mass gainers available in the market: The Best Mass Gainers Around the World
Use the above list as a starting point and research more on the mass gainer that best suits your needs. Make sure that you purchase all your nutrition products from a genuine source. Apart from usual weight gain supplements, don’t forget to invest in multi-vitamins, to keep your body functioning properly and keep it healthy.
NOTE: Always consult your doctor before starting any dietary supplement.
Recommended: There are tons of supplements available in the market, but you do not need all of them. I’ve already done the work so you don’t have to. Here’s a list of top weight gain supplements that you need to put on weight.
The last, but also the most important, is to track progress.
This point not just applies to nutrition, but also your training and recovery part. Tracking your progress might seem a difficult and tedious task, but when you see results, you’ll be self-motivated towards your fitness routine.
For the nutrition part, tracking your calories allows you to examine if you’re eating enough to put on weight, and if not, what else you can do to your existing diet to meet your requirement. It also allows you to keep your weight gain in check, and make sure that you gain more of muscle and less of unnecessary fat.
For most people, tracking calories might mean checking each food item’s label before eating. Some of this is true, but there are easier ways to do this. How I like to do it is that first, I calculate the total calories I need each day by using the Daily Calorie Calculator. Second, I list the food items in my grocery or the ones I like and calculate the rough calories in each serving of the food items. This will only be needed for the first time. Once you have the idea, include the list of foods in a way that meets your calorie requirements!
Make sure that you do not complicate the process by calculating and reading everything that you put in. Just get a rough idea of calories that you’re consuming and track progress after each week. If you’re gaining optimum weight, stick to the diet. If you feel that you’re not gaining the amount of weight that you wish to, increase the calories.
In case you require, there are also apps for doing this work of calculating calories and macro-nutrients for you. I’ll be doing a separate article on this in detail, so stay tuned.
Coming over to the training part, you must track your workouts and everything in between. This is not just to get an idea of how much you lift, but it also helps you focus on progressive overload.
The Progressive Overload Principle, in short, means that your body will only grow once it is given an opportunity to grow. This opportunity will arise only when you force and challenge your body to a tension that it hasn’t experienced before. We’ll discuss more about this in the Training Section below.
About recovery, your body will never grow if you keep pushing it to the limits, without giving it proper rest and time to recover. This is why getting enough quality sleep is important, and so is to take proper rest days. We’ll cover this in the Recover section below.
Lift Heavy Weight
Something that everybody is sure of. There’s no way you’re getting big and stronger if you keep lifting the same light-weight throughout the year.
In order to achieve hypertrophy, which is the increase and growth of muscle cells, you need to stay in an 8-12 rep range, according to reports.
Our bodies are complex, and their most important job is to keep you alive. For this, it’ll adapt to any environment that you put it into. Hence you might want to keep it challenged, by lifting more weight every time your body adapts and easily performs the same reps on a weight range.
Focus on Compound Movements
A compound exercise, as opposed to isolation exercise, is an exercise that involves multiple muscle groups and joints at a particular point. In short, compound exercises are the ones that help you build most of your muscles. Apart from this, they also help your body in increasing strength.
In general, compound movements maximize your muscle recruitment and stimulus for growth. Some of the best examples of compound movements include exercises such as Squats, Deadlift and Bench Press.
For instance, Squats involve quadriceps, glutes and, hamstrings all at the same time, while also requiring your knees, ankle and, hip joint to participate in the movement. Deadlift, also known as the king of upper body exercises, involves almost all muscle groups in the posterior side of your body, while also recruiting muscles such as your hamstrings and glutes.
If you’re looking to gain weight and build muscle, focusing on heavy compound movements will help you reach this goal faster. The best way is to always start your workout with 2-3 heavy compound lifts, followed by 1-2 isolation exercises to fully engage a specific muscle.
For a complete list of exercises that you should regularly include in your workouts, here’s a complete guide on the best exercises to gain weight.
Related: While you definitely need to eat high quality calorie-dense foods in order you feed your muscles and help you lift more, there are also supplements that can help you with the lifting part. Creatine is one such supplement. Here’s an article on how you can use creatine to gain weight.
As talked before, our bodies are designed to protect us and adapt to any given environment. They’ll only grow once they’re given a reason to. Which is why it is important to always challenge your body.
Progressive overload basically means that your body must be challenged with a tension that is more than it has experienced before. You can either do this by increasing the resistance, increasing the volume, increasing the reps, decreasing the rest time between sets or increasing your training frequency.
The idea is to keep your muscles shocked, by using either of the methods mentioned above. It’s important that you only make minor changes, by following one of the methods above. Once your body gets adapted to it, which it will, it’ll be time that you move on to the next option.
This isn’t anything new. No matter what your fitness goals are, no matter what stage you’re at, you always need to keep a check on your form.
An improper form will not only limit your gains, but it might also lead to severe injuries which will further delay the whole process.
While starting, always make sure that you’ve researched on the type of exercise you’re going to perform and make sure you know the proper posture for it. Even better, taking help from a personal or gym trainer in the beginning should be your best bet. Once you’re aware of the correct posture and techniques, you could work out on your own.
Limit Your Cardio
Since your goal is to stay in a calorie surplus, doing too much cardio wouldn’t be a good idea. When you’re doing everything you can to get more calories in your body than you burn, burning calories on the other side might dis-balance the equation.
Hence, either avoid or limit your cardio to a minimum. A short session of cardio should be good for your overall fitness and health, but make sure you’re not overdoing it.
Recommended: Top Exercise to Gain Weight
Rest and Recovery
Get Enough Sleep
You could be working out with extreme intensity and eating well but still not see the results you want if you do not give your body enough time to recover. Legend says you do not build muscle in the gym, but when you’re asleep.
When you create-micro tears in your body during work out, these tissues need to be fed and given time to recover and grow back stronger. Once given enough nutrients, the last step is to give them time to recover. This is where getting enough sleep comes into play.
While sleeping, most of the blood supply is available to muscles, helping facilitate recovery and growth. Your body also releases Growth Hormone during this period, which is the main hormone to stimulate muscle repair and growth. Compromising on your sleep might not only cause a deficiency in growth hormone, but might also make sure that the workouts you do and the nutrition you take goes waste.
If you have your training and nutrition part on point, make sure you get at least 7-9 hours of sound sleep everyday to keep the gains going.
Stay Away from Over-training
If you’re feeling symptoms such as insomnia, lack of appetite or chronic fatigue, your body might be going through over-training. While training with high intensity is definitely something you need to do, you also have to stay away from over-training as much as possible.
Not just tiredness and loss of appetite, but over-training might also make your muscles weaker or smaller due to excessive training and not enough nutrition.
Hence, make sure your workout doesn’t include hours of training and only small portion of nutrition. An ideal workout would last for 45-60 minutes, and the rest of the day should be devoted towards getting enough rest and proper nutrition. There are ways to gain weight, but over-training isn’t one of them.
Best Weight Gain Program
No matter how much information there is on the internet, none of it matters if you aren’t able to implement it all in to your routine. Even more, you should be able to gather only the information that is relevant to you as a hard-gainer, and only work on those that are highly specific to your body and specific goals.
However, considering that there’s a huge portal of information about weight gain on the internet, it can sometimes be difficult to grasp it all, and differentiate what is right and what is wrong information.
Combined with the fact that everybody on the internet wants to make money, you might get exposed to products, supplements or even programs that may not be useful, but in fact harmful for your body in the long run.
Even though I’ve gone through the hit-and-trial method of gaining healthy weight, trying different workout plans, supplements, and nutrition program, I do not suggest you going through the same.
The reason is simple, not everybody has the time and effort to go through testing each and every product, and then going through the consequences, and then getting back on the track.
For you, the case might be simple. All you want is to gain healthy weight, with limited budget, time and effort. You might want to go with a program that has already worked for thousands of people, and all you will have to do is follow the program religiously.
If I were to choose for myself, I would go for a scientific-weight gain program from several reasons. First, I will not have to constantly spend on products that may not workout. Second, I will save money and time in the long run by using science that professionals have created for me. Third, I will be able to have mental peace on the investment that I make, given that the program I’ve chosen has worked for thousands of people like me, and has a refund policy in case it doesn’t work out.
If you’re looking for a program that takes care of the Nutrition, Workout and Supplement part of healthy weight gain, and guarantees you results with a refund policy, checkout the review below:
Frequently Asked Questions
How do we gain weight?
Body composition depends on a lot of factors. The difference between our calorie consumption and calorie expenditure over a period of time decides either we’ll gain, lose or maintain our current weight. Factors like daily activity levels, metabolism, genetics, sports activity involved in, age and hormones play a big role in this.
For example, if our body needs 3000 kcal a day to maintain our current weight and perform body functions, eating a surplus over this number would make you put on weight while consuming a number below this number will lead to weight loss. Generally, a surplus of 300-500 calories is enough to put on healthy weight while minimizing any fat gains, considering that most of your calories come from healthy calorie-dense foods.
Since body composition is the ratio of fat and non-fat mass in the body, a healthy body composition would be the one with a low percentage of fat and a higher percentage of muscle. This is why when you plan on gaining weight, do not go overboard by eating anything and everything you can that involves junk food and sodas. Try to stick to healthy, calorie-dense foods for the most part of your diet and fulfill the gaps with the foods that you like.
What is the best way to gain weight?
The best way to accomplish any fitness goal is to track your calories, maintain progressive overload in the workout and get adequate rest. Similar is the case in gaining healthy weight and putting on muscle.
How can I gain weight in 7 days?
There’s only a limit to what your body can accomplish in a particular period, and going overboard would only make things worse. While you can put on some good amount of weight in a week’s time, most of it will be unnecessary fat which would cause more harm than good in the long run.
If you’re looking to gain weight irrespective of fat, you could eat a calorie surplus of 600-1000 calories above your maintenance levels. This might add some fat to your gains but will make sure that you gain a good amount of weight in a week.
However, if you’re only looking to put on lean muscle, you should aim between 300-500 calories above your maintenance, coming from high-quality whole foods. The optimum amount of weight gain during a week’s period would be somewhere around 1 pounds.
It’s is hard to figure out how much weight you can gain in a week’s time, since it depends on a lot of factors. Hence, my advice for the easiest way to gain weight is always to start with a 300-500 calorie surplus and then slightly increase the calories until you reach your goals.
What is the fastest way to gain weight?
The fastest way to gain weight is to eat everything you can, but this would only make you gain more of fat rather than muscle. There’s a limit to the amount of muscle you can gain in a particular time, and anything more than that would be unnecessary fat.
For example, the GOMAD plan makes you drink a gallon of milk a day, adding 2400 calories to your daily routine. While this definitely looks enticing and is a fast way to gain weight, the excess calories over your current maintenance levels would only make you put on more of weight than muscle. Thus, this method is only for extreme hard-gainers and ectomorphs who only wish to put on weight, not caring about fat or muscle.
What to eat to gain weight?
This has already been covered above in the Nutrition section. But in short, in order to gain healthy weight, you need to make certain food choices and focus more on foods that are highly nutritious but also high in calories at the same time.
Consuming liquid calories is another great way to put on weight and not feel full. This is because liquids digest faster than whole foods, and do not make you full compared to solid foods.
Why Can’t I gain weight even after eating a lot?
Keeping health disorders aside, the only reason you’re not seeing results is that your calorie consumption is not up to the mark. Period!
As in the case of most hard-gainers, eating a big meal in a day does not qualify as a calorie surplus. When you eat a big meal and keep all your other meals small, you’re only consuming enough calories to maintain your current weight.
For example, consider that you need 3500kcal/day in order to gain weight. You eat a 1200 calorie pizza in the afternoon, but as breakfast and dinner you eat the same 700-800 calorie meal. This would only total out to be between 2600-2800, which is lesser than your required calories.
Hence, if you’re looking for an answer on how to gain weight with a high metabolism, it is important that you start tracking calories and see if you’re consistently maintaining a calorie surplus. The easiest way to do this is mentioned above. These are, to increase the quantity of each meal and then increase the number of meals. Eating a calorie surplus in every meal will ensure that you constantly stay over your maintenance calorie levels, thus helping you put on weight!
Follow the above mentioned weight gain tips and you’re surely putting on that serious mass you’ve been waiting for. To sum up, the only thing to make sure while gaining weight fast is that you stay in a calorie surplus. At first, you might slightly need to over-feed and force your body a little to eat more, but once you start working out and eating more, your body will start going and adapting to the calorie surplus.
How much fat and muscle you gain depends on the amount of extra calories you consume over a period of time, and if you have a high metabolism, keep experimenting with the extra calories to find the sweet spot where you gain maximum muscle.
At the end of the day, the answer to your question: how to gain weight with a fast metabolism largely depends on what and how much you eat, along with how you train and how much rest you give to your body. Make sure not to stress about the above points and make small changes to your diet, thus turning all of it into a healthy lifestyle. Take out time to reward your body with cheat meals here and there, and stay as consistent with diet as you do with your workout.
And lastly, don’t forget to tell us all about your weight gain journey through the comment section below!