How to Gain Weight on a Vegan Diet: 7 Steps
In this guide
Written by James, founder of Flaming Phoenix and the maker of Phoenix Bars. Updated October 2026.
To gain weight on a vegan diet, eat about 300 to 500 calories a day more than you do now, and get them from foods that are dense, not bulky. Plant foods are high in fibre and water, so most vegans who struggle to gain are full long before they have eaten enough. The seven steps below fix that in order.
Step 1: Set a target
The NHS suggests adults gain weight gradually by adding around 300 to 500 calories a day. If you do not know your starting point, the weight gain calculator gives you one, and how many calories to gain weight explains the sums. The method for any diet, vegan or not, is in how to gain weight.
Step 2: Cut the bulk, not the plants
Fullness is the real obstacle. Swap some wholegrain pasta and brown rice for white, which the Vegan Society suggests when bulk is a problem. Cook vegetables instead of eating them raw. Choose dried fruit over fresh some of the time. You keep the plants and lose the volume. More in high calorie low volume foods.
Step 3: Add fat to every plate
A tablespoon of olive or rapeseed oil is about 120 calories and changes nothing about how full you feel. Two tablespoons of peanut butter are about 185. Half an avocado is about 135. Stir, drizzle or spread one of them onto each meal.
Step 4: Check your plant milk
Plant milks differ more than people expect. One NHS leaflet lists soya milk at about 88 calories per 200ml and almond milk at about 44. If you use 500ml a day, switching from almond to soya adds about 110 calories and more protein. Pick a fortified one.
Step 5: Drink some of your calories
A shake goes down more easily than a plate. Blend 300ml fortified soya milk, 50g oats, two tablespoons of peanut butter, a banana and two Medjool dates for about 730 calories. Have it between meals so it adds to food and does not replace it. Recipes are in homemade weight gainer shakes, and powders are compared in best vegan mass gainer.
Step 6: Eat more often and keep dense snacks close
Three meals and two or three snacks beat three large meals. Good vegan snacks are a handful of nuts (about 185 calories for 30g), hummus and pitta, dates, dark chocolate and oat bars. The full ranking is in high calorie vegan foods.
Step 7: Cover the nutrients while you add calories
More food is a good moment to check the basics. NHS dietitians advise the following for a vegan diet:
- Vitamin B12 from fortified foods, at least 3 micrograms a day, or a 10 microgram daily supplement.
- Iodine at about 140 micrograms a day, usually from a supplement or fortified plant milk.
- Vitamin D at 10 micrograms a day from October to March.
- A daily omega-3 source such as ground linseed, chia, walnuts or rapeseed oil.
Include protein at each meal from tofu, tempeh, beans, lentils or soya milk. If you train, strength work helps the extra weight go on as muscle.
A worked example: about 520 extra calories, same meals
You do not need a new diet. Take an ordinary vegan day and make four changes:
- Make breakfast porridge with 300ml soya milk in place of almond milk: about 65 more.
- Stir two tablespoons of peanut butter into that porridge: about 185 more.
- Add a tablespoon of olive oil to lunchtime soup: about 120 more.
- Have 50g of hummus with the bread: about 150 more.
That is about 520 calories, and the meals look the same. For a full week at three calorie levels, see the weight gain meal plan, which has vegan swaps.
When cooking is not going to happen
Some days need something with no preparation. Our high calorie bars for weight gain are vegan, with up to 557 calories and 18 to 19g of protein in a compact, lightweight 120g bar. “I’ve always struggled to get enough calories in, especially while on the move, and these bars really helped with that,” wrote Brittney S. in April 2025. “They gave me so many calories without having to eat very much,” wrote Dom B. in August 2025. Phoenix Bars cost £5.25 each. Other options are in best vegan energy bars UK.
How to tell it is working
Weigh yourself once a week, same day, same time. A quarter to half a kilo a week is a sensible pace as a rule of thumb. If nothing has moved after two weeks, add another 200 to 300 calories. If you are stuck, why can’t I gain weight covers the usual reasons. The NHS advises seeing a GP if you have lost weight suddenly or without changing how you eat.
Common questions
Why is it hard to gain weight as a vegan? Fibre and water. Plant foods fill you up for fewer calories, so the fix is density: fats, nuts, dried fruit and drinks.
Can you gain weight on a vegan diet without protein powder? Yes. Soya milk, tofu, tempeh, lentils, nuts and oats provide protein, and the calories come from fats and starches.
What is the highest calorie vegan food? Oils, at about 900 calories per 100g, then nuts and nut butters at 550 to 750.
Sources: NHS, healthy ways to gain weight. NHS, the vegan diet. Royal Devon NHS, a nourishing dairy-free or vegan diet. The Vegan Society, fuelling an active lifestyle.
Big calories. Small bar.
Up to 557 calories in a compact, lightweight bar of only 120g, with up to 66g of carbs and 19g of protein. Eat it whole, break it into pieces over a few hours, or mix it with water or milk for porridge.
Easy to eat, easy to digest and not sickly sweet. Customers have eaten them at -45°C and through the heat of the Marathon des Sables, and they keep for up to 2 years, so they work on a mountain, on a night shift, or at home on days when eating enough feels hard.
- 557 calories in only 120g (529 to 557 by flavour)
- 4.6 calories per gram
- 66g carbs per bar (up to)
- 19g protein per bar (up to)
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