Tips to Gain Weight From a Registered Dietitian | How to Deal with a Fast Metabolism

Medically reviewed by Abbey Sharp, Registered Dietitian (RD), BASc.

Unsure how to gain weight with a fast metabolism? We share 13 dietitian approved tips to gain weight in a healthy way.

Weight Gain Cheat Sheet

Blue plate with letters spelling the words weight gain.

Why Might Someone Want GAIN Weight?

Theres no question that the common narrative in our society is all about how to LOSE weight, but there are a number of reasons why someone may be looking to purposefully gain weight to support their health and wellness goals (even with a fast metabolism).

Being Underweight

Whether you are underweight from under-eating, or you just have a fast metabolism, not eating enough to meet your nutrient needs can result in malnutrition, vitamin deficiencies, osteoporosis, decreased immune function, fertility issues, growth and development problems, and digestive issues. Just to name a few. So gaining weight and eating more in these circumstances my help to better support overall health.

Eating Disorder Recovery

Folks in eating disorder recovery will often need to weight restore and improve their nutrition status. However, their hunger cues may be consequently blunted after years of food restriction which means that they may need to lean on other strategies besides their hunger signals to increase their caloric intake.

**Note: If you’ve been severely restricting and are now trying to eat more to gain weight, I strongly advise speaking to a dietitian before beginning this journey as introducing too many calories too quickly can put you at risk for re-feeding syndrome.

Sports Performance

Others may be looking to gain weight for performance reasons related to sport or fitness goals or just your daily activities of life.

Low Appetite

A low appetite can be related to medications like SSRIs, stimulants for ADHD, or health conditions like digestive disorders, anxiety and depression.

Whatever the reason for intentional weight gain, some folks may require expert advice that supports long term health and doesn’t just mean added calories in the form of calorie-dense and nutrient-poor foods like pastries, fries, and soda. While these foods can absolutely be part of the plan, we still want to make sure we are feeling our best in this process and that means prioritizing foods that support our energy needs, cognitive capacity, and digestion. So with that in mind, here are my top dietitian approved strategies to gain weight with a fast metabolism.

Tips to Gain Weight with a Fast Metabolism

Focus on Calorie Dense Foods

So this is a bit of a no-brainer, since foods that are super high volume but low in calories can take up precious real estate in your tummy and make it hard to get the nutrition you need. Instead, you want to focus on calorie dense foods that are lower in water and fibre content, and higher in healthy fats or protein. This includes foods like full-fat dairy, avocado, nuts and seeds, salad dressing, added oil, dried fruit and smoothies. Of course we still need veggies and fruit, but make sure to eat them in combination with lots of nuts, dressing, starchy veggies, and whole grains.

Avocado and almonds in a red bag on an orange background.

Eat Smaller Meals More Frequently

Eating smaller and more frequent meals not only provides more opportunities to get calories in, but is also slightly easier on your digestion and can be psychologically less overwhelming. So aim to eat a portion you can tolerate every 2 to 4 hours each day, or aim for 3 meals and 2 to 3 snacks per day.

Hydrate with Extra Calories

One of the most common tips to gain weight is to go for liquid calories, and for good reason. Research suggests that it’s a lot easier to drink calories than to eat them, which is why adding calories to your beverages can be more feasible, physically and psychologically, than chewing a lot of food at once. For example, one cup of orange juice is the equivalent of approximately 3 whole oranges – but it’s a lot faster and easier to drink a cup of juice than peel, slice and chew the equivalent amount of fruit.

While you should still continue to prioritize water as your beverage of choice, you can also meet a lot of your hydration AND calorie needs by adding juice, milk, kefir, and smoothies that contain protein powder, nut butter, and/or full-fat yogurt.

You can also swap in whole milk, cream, canned coconut milk, evaporated milk, or juice in place of water in a wide range of recipes. Whether you are making cereal, oatmeal, coffee, soups, sauces, or spreads, adding a calorie-filled liquid can not only add flavour, but extra calories without any additional “bulk” or the perception of “more food” in your day.

Hands pouring a greem smoothie into a clear glass.

Hydrate AFTER You Eat

Drinking a ton of water before a meal can stretch the stomach temporarily and make it less comfortable for you to fill it with a nutrient-dense meal. Of course hydrate when you are feeling thirsty, but because water has no calories, I would recommend waiting until AFTER you’ve gotten your food fill.

Dip it Up

Let’s be honest, everything tastes better with sauce. Now is the time to make sauces, dips, and dressings your BFF. Whether that’s adding hummus with crackers, mixing some chocolate into Greek yogurt, or drizzling tahini over grilled veggies and meats, it’s a great way to add calories without a lot of volume.

One of my personal favourites from my cookbook, The Mindful Glow, is my Thai peanut hummus which is loaded with protein and healthy fats. But when in doubt, olive oil or butter also does the trick. Oils and fats are a really easy way to add flavour, calories, and nutrition without adding bulk or volume to your meal.

Add “Sprinkles” to Anything

Take a tip out of my toddler parenting tip book: sprinkles make eating more fun. And yes, this could totally be standard rainbow sprinkles, but it could also be any nutritious yummies like crumbled cheese, nuts, and seeds.

My dedicated followers will know that I sprinkle hemp hearts onto basically everything I eat: smoothies, soups, salads, avocado toast, you name. This is because one tablespoon of hemp hearts contains 50 calories with 5g of healthy fats and over 3g of protein. They also add a really yummy nutty flavour that I thoroughly enjoy.

Olive oil being poured on a salad with cheese and olives to help gain weight.

Focus on Making Food Fun

One of the biggest complaints I often hear from people is that eating feels like a chore. Ironically, boredom is also one of the biggest complaints that people have on weight loss diets as well. But the sky is literally the limit when true abundance is the goal. So make mealtimes as fun, exciting, and special by busting out a new cookbook, experimenting in the kitchen, and heading full force into flavour town. When each meal is something you are genuinely looking forward to because it’s new and novel, you are less likely to skip it or forget to eat.

Be Prepared

Healthy eating requires a certain level of intentional action especially when you are trying to eat to gain weight but don’t have the biological drive to eat. So in order to reach your weight gain goals, eating has to be easy and accessible.

I recommend always having a few pre-prepared meals, meal components, or snacks on hand that you can really easily just pop in the microwave or throw in your work bag. Try to double or triple a recipe so you can freeze some for another night, or if you are cooking some sort of protein, make extra and keep it in the fridge for easy meals.

As for snacks, I have some delicious make ahead snack recipes on the blog, such as these Easy No Bake Protein Bars. However, not all snacks need to be homemade. I think there are a lot of fantastic store bought options that can help you meet your needs between meals or help to supplement meals. Some easy energy dense ideas that I like to lean on for snack time include nut or seed based granola bars like KIND Bars, energy bars like CLIF Bars, energy balls like the ones from NOMZ, crackers with peanut butter, cheese strings and fruit and trail mixes or nut mixes.

Two granola bars against a white background as a tip to gain weight.

Develop and Stick to a Meal Routine

This tip to gain weight is particularly important for folks in eating disorder recovery or those who don’t have clear hunger cues because you basically need to train your body to expect and need food. We call this mechanical feeding.

By feeding your body regularly and routinely, you start to actually feel hunger at those specific times as your metabolism starts to kick back into gear. For some people, the easiest thing to do is to actually set alarms or recurring meetings in your calendar, basically making a commitment to yourself and your body to take care of it at those times.

I know it feels really unnatural, and maybe some of you may feel even a little selfish or frivolous devoting so much time in the day to yourself, especially when you aren’t even responding to a “need”. However, I promise with time, your body will respond with a reinforcing cue.

Get Social

Try to eat in the company of others when you can. Loneliness and depression are huge sources of low appetite and can also reinforce restrictive behaviours. However, eating with others not only makes the experience more novel and fun, but research suggests that people do tend to eat more in the presence of others. So invite family for dinner, pick up smoothies with a friend on a walk, do a zoom cake and coffee catch up with a friend or make a point to join a coworker for lunch.

Birds eye view of a group of people eating around a table with food.

Focus on Cold and Odourless Items

This tip to gain weight is particularly important for those struggling with low appetite or nausea, possibly related to pregnancy, medication or just emotional exhaustion trying to eat beyond one’s cues.

If you are really having a rough eating day, you may find it best to avoid anything hot or too aromatic. A smoothie or a smoothie frozen into a homemade popsicle might be easier to stomach than a fragrant aromatic stir fry or pot of chilli on those days when nothing sounds appealing.

Everyone is going to figure out what is best “tolerated” for them, and of course, depending on one’s culture and their own personal “comfort foods”, something hot and fragrant might just do the trick. But generally speaking, folks struggling with nausea report neutral foods go down best.

Make a Safe Meal List

I don’t mean “safe” foods that are “diet friendly” and low in calories. I mean foods that you feel you can tolerate when you’re struggling with low appetite, nausea, or lack of motivation and nothing sounds good to eat.

This is for those days when you’ve asked yourself “what do I feel like today” and nothing seems to come to mind. You need a list of easy to access foods that you at least feel neutral about. You don’t have to be jazzed about them, but they’re familiar and accessible enough that if you’re having a day where you just can’t handle another meal or snack, you know this list will be there for you. So these may be more bland and simple “comfort” foods like peanut butter toast or crackers and cheese, or they could be something unique to your culture or childhood. Not every meal or snack needs to be revolutionary – sometimes they just need to nourish you in that moment to help you get by.

Bottom Line

I hope those tips to gain weight with a fast metabolism (or low appetite, etc.) are helpful for those who may be embarking on a weight gain journey, or perhaps just looking to incorporate some new sustainable nutrition tips into their diet. However, I do want to emphasize that I strongly recommend working with an RD or another medical professional if you are in a situation that requires serious weight restoration. As I said earlier, in a lot of cases, it can be dangerous to just jump “all in” if you’re starting from a place of severe restriction. Always speak to a doctor and a registered dietitian about your unique case.

Tips to Gain Weight From a Registered Dietitian | How to Deal with a Fast Metabolism