How do Pescatarians gain weight?

October 7, 2025 •

2 min read

While often associated with weight loss, a well-planned pescatarian diet can effectively facilitate healthy weight gain by consistently creating a calorie surplus. This guide explores how do pescatarians gain weight by focusing on high-calorie, nutrient-dense, and satisfying meal strategies.

Quick Summary

A pescatarian can gain weight by increasing calorie intake through a strategic diet plan. Focusing on protein-rich seafood, healthy fats, and complex carbohydrates supports healthy muscle and mass development.

Key Points

Create a Caloric Surplus: To gain weight, consume more calories than you expend daily, aiming for 2,000–2,500 calories as a starting point.
Prioritize Nutrient-Dense Foods: Focus on calorie-rich, healthy options like fatty fish, nuts, avocados, and whole grains to ensure quality weight gain.
Boost Protein Intake: Incorporate high-quality protein from fish, seafood, eggs/dairy (if included), and legumes to support muscle growth.
Strategically Use Healthy Fats: Increase calorie density by adding healthy fats from oils, nuts, and avocados to your meals and snacks.
Eat Frequently and Plan Ahead: Space out meals and snacks throughout the day and consider meal prepping nutrient-dense options for consistency.
Avoid Empty Calories: Limit reliance on processed foods and fried fish, which offer calories without substantial nutritional benefit.

To gain weight as a pescatarian, consuming more calories than your body burns is the core principle. This requires a strategic focus on nutrient-dense options for healthy, sustainable weight gain. The pescatarian diet supports this through its flexibility, incorporating protein and healthy fats from fish alongside diverse plant-based foods.

The Caloric Surplus Equation

Achieving a caloric surplus involves consuming nutrient-dense foods rather than empty calories. A common starting point for weight gain is 2,000–2,500 calories per day, adjusted for individual needs and activity levels.

Nutrient-dense, calorie-rich foods suitable for a pescatarian include fatty fish (salmon, mackerel, herring), nuts and nut butters, avocado, whole grains (quinoa, brown rice, oats), and dried fruits.

Protein Sources for Muscle Growth

Building muscle mass requires adequate protein intake. Pescatarian options include fish and shellfish, eggs and dairy (if consumed), and plant-based sources like legumes, soy products, and quinoa.

Healthy Fats to Boost Calories

Healthy fats are calorie-dense and important for weight gain, hormone regulation, and nutrient absorption. Sources include fatty fish, nuts and seeds, avocados, and healthy oils like olive oil.

Complex Carbohydrates for Energy

Complex carbohydrates provide energy and support muscle glycogen stores. Options include whole grains, starchy vegetables, and legumes.

Comparison: Pescatarian vs. Vegetarian Weight Gain

Including seafood gives pescatarians advantages in certain nutrients compared to vegetarians, although both diets can support weight gain with proper planning. The table below outlines key differences:


Feature	Pescatarian Weight Gain	Vegetarian Weight Gain
Primary Protein Sources	Fish, seafood, eggs/dairy, plant sources	Eggs/dairy, plant sources
Omega-3s (EPA & DHA)	Rich sources from fatty fish	Relies on ALA from plants or supplements
Vitamin B12	Easily obtained from seafood, eggs, dairy	Requires careful planning or supplementation
Ease of Calorie Surplus	Easier with calorie-dense fish and fats	Requires more careful food selection and portioning
Mercury Risk	Requires selecting low-mercury fish	No mercury risk from seafood

Strategic Eating for Healthy Weight Gain

Adopt strategic eating habits such as eating frequently (three meals plus several high-calorie snacks), incorporating nutrient-dense smoothies, increasing portion sizes, and adding calorie-rich toppings like olive oil, nuts, and seeds.

Potential Pitfalls to Avoid

To avoid unhealthy weight gain, limit processed foods and fried fish, which lack nutritional value. Be mindful of mercury levels by choosing low-mercury fish options like salmon, cod, and canned light tuna.

Conclusion

Achieving healthy weight gain as a pescatarian is possible with a focus on a moderate caloric surplus and nutrient-dense foods. Emphasizing fatty fish, healthy fats from sources like nuts and avocados, and complex carbohydrates from whole grains provides a foundation for sustainable weight gain and muscle development, leveraging the benefits of both seafood and plant-based foods.

{Link: WHO https://www.who.int/news-room/fact-sheets/detail/healthy-diet}

Frequently Asked Questions

To gain weight, a pescatarian typically needs a caloric surplus of 300–500 extra calories per day beyond their maintenance level. A daily intake of 2,000–2,500 calories is a good starting point, adjustable based on activity level.

Fatty fish like salmon, mackerel, and sardines are ideal for weight gain because they are high in protein and energy-dense omega-3 fatty acids. It is recommended to choose low-mercury fish and vary your intake.

Yes, absolutely. The pescatarian diet provides ample protein from sources like fish, eggs, dairy, legumes, and tofu, which is essential for muscle growth when combined with resistance training.

High-calorie, homemade protein smoothies are an excellent way for pescatarians to gain weight healthily. Ingredients like nuts, seeds, full-fat Greek yogurt, and protein powder can significantly boost your calorie intake.

To avoid unhealthy weight gain, focus on whole, nutrient-dense foods rather than processed or fried options. Pay attention to portion sizes and ensure you are eating a balanced mix of protein, complex carbs, and healthy fats.

Plant-based high-calorie foods for pescatarians include nuts, seeds, avocados, nut butters, whole grains like quinoa and oats, starchy vegetables like sweet potatoes, and legumes such as lentils and chickpeas.

To add calories without excessive fullness, incorporate calorie-dense but low-volume additions. This includes using extra olive oil on salads, sprinkling nuts and seeds on dishes, or adding nut butter to oatmeal.