The low FODMAP diet has become increasingly popular for managing digestive issues like IBS, SIBO, and leaky gut. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols. These are short chain carbohydrates that can be hard to digest for some people, leading to gas, bloating, pain and other unwanted symptoms. Many find relief by following a low FODMAP diet, which eliminates high FODMAP foods.
Fish can be a great source of protein on a low FODMAP diet, but only certain types are considered low FODMAP. That’s because some fish contain FODMAPs while others don’t. So which fish can you eat freely on a low FODMAP diet, and which should you avoid or limit? Let’s take a detailed look.
What are FODMAPs and the low FODMAP diet?
FODMAPs refer to certain types of carbohydrates that may be poorly absorbed in the small intestine of some people. The acronym FODMAP stands for:
– Fermentable – meaning they are broken down (fermented) by bacteria in the large intestine
– Oligosaccharides – fructans and galactooligosaccharides (GOS)
– Disaccharides – lactose
– Monosaccharides – fructose
– Polyols – sugar alcohols like sorbitol, mannitol, xylitol and maltitol
Foods that are high in these FODMAPs can cause digestive distress in two key ways:
1. They draw fluid into the intestinal lumen (osmotic effect). This excess fluid can lead to diarrhea and abdominal pain.
2. They are rapidly fermented by intestinal bacteria, producing excess gas, bloating and flatulence.
The low FODMAP diet involves significantly reducing intake of high FODMAP foods for 4-8 weeks. This “elimination phase” helps improve symptoms by lowering fermentable carbohydrate intake. Foods are then re-introduced one at a time to identify personal tolerance thresholds. Those that trigger symptoms are avoided long-term.
Numerous studies show the low FODMAP diet improves symptoms in 50-80% of IBS patients. It helps those with IBS-D (diarrhea predominant), IBS-C (constipation predominant) and IBS-M (mixed diarrhea and constipation). The diet also benefits other functional gut disorders like SIBO and leaky gut syndrome.
Why choose low FODMAP fish?
Fish can be a great source of protein in a low FODMAP diet. It provides a lean, low-fat protein option without the FODMAPs found in many other animal proteins like dairy.
However, not all fish are low FODMAP. Some contain significant amounts of fructose or GOS, making them a high FODMAP choice. Consuming these varieties could exacerbate digestive symptoms in sensitive individuals.
Choosing low FODMAP fish ensures you can enjoy the nutritional benefits of fish without triggering gut issues. These include:
– Excellent source of high quality protein
– Rich in omega-3 fatty acids EPA and DHA
– Good source of vitamins like selenium, niacin, vitamin B12 and vitamin D
– Contains important minerals like potassium, zinc and iron
– Low in saturated fat and calories
Let’s explore which fish are low in FODMAPs, and which to limit on a low FODMAP diet.
Low FODMAP fish
Many types of fresh, plain fish are considered low FODMAP in 4-6 ounce serving sizes. These include:
| Type of Fish | Notes |
|---|---|
| Anchovies | Low in FODMAPs and rich in omega-3s |
| Arctic char | Has a delicate flavor like trout or salmon |
| Barramundi | Mild, flaky white fish from Australia |
| Bass | Popular for grilling and baking, very versatile |
| Black cod | Buttery, rich flavor. Also called sablefish. |
| Catfish | Mild tasting white fish from US rivers and lakes |
| Cod | Delicate, flaky white fish used in fish and chips |
| Flounder | Mild, thin white fish perfect for frying or baking |
| Grouper | Flavorful fish found in tropical waters |
| Haddock | Closely related to cod, with a subtle sweet flavor |
| Halibut | Lean, firm and flaky with a mild taste |
| Herring | Small fish popularly pickled or smoked |
| Mackerel | Rich, oily fish with lots of omega-3s |
| Mahi mahi | Tender white fish with a delicate, sweet flavor |
| Monkfish | Firm white fish with a lobster-like flavor |
| Ocean perch | Also called red fish, has a mild, delicate flavor |
| Orange roughy | Mild, slightly sweet flavor |
| Perch | Small freshwater fish with a light flavor |
| Pike | Freshwater fish with a flaky texture and mild taste |
| Pollock | Member of the cod family, widely used in fish sticks |
| Pomfret | Buttery texture and sweet, delicate flavor |
| Red snapper | Mild, slightly sweet tasting white fish |
| Sardine | Small, oily fish packed with nutrients |
| Sole | Flatfish with a delicate, almost sweet flavor |
| Striped bass | Silky, moist flesh with a fresh, clean flavor |
| Swordfish | Meaty texture and slightly sweet flavor |
| Tilapia | Widely available mild flavored white fish |
| Trout | Delicate flavor ranging from mild to richly flavored |
| Tuna | Firm, meaty fish perfect for grilling |
| Turbot | Expensive European flatfish similar to halibut |
| Walleye | Freshwater white fish with a flaky texture |
As shown in the table, most white fish are low FODMAP in normal serving sizes since they are low in FODMAP-containing carbohydrates.
Oily fish rich in omega-3s like anchovies, herring, mackerel, sardines and salmon are also low FODMAP. Just be mindful of serving sizes, since too much of any fish could provide excess FODMAPs.
High FODMAP fish
While most plain fish fillets are low FODMAP, some specific fish should be avoided or limited on a strict low FODMAP diet. These include:
| Type of Fish | FODMAP Content |
|---|---|
| Barramundi (with skin) | Contains GOS |
| Fish roe (eggs) | High in fructose |
| Salmon | Contains sorbitol |
| Snapper (with skin) | Contains GOS |
Let’s look at each of these high FODMAP fish in more detail:
Barramundi and snapper with skin – The skin of these fish contains moderate amounts of GOS, a type of FODMAP. Eating more than about 1.5 ounces (40g) of the skin could contribute too much total FODMAP. Removing the skin lowers the FODMAP content.
Fish roe – Fish eggs like salmon roe and herring roe are concentrated sources of fructose, testing high on the FODMAP scale. Limit to about 1 tablespoon (15g) per sitting if following a strict low FODMAP diet.
Salmon – While the flesh is low FODMAP by itself, salmon contains higher amounts of the polyol sorbitol compared to other fish. Sticking to a 4-6 ounce serving is recommended.
So in summary, fish are predominantly low in FODMAPs but a few specific preparations should be limited. Watch out for fish skin and roe, and keep salmon portions moderate.
Tips for preparing low FODMAP fish
Here are some tips for choosing and preparing fish on a low FODMAP diet:
– Choose plain, fresh or frozen fillets without added sauces or rubs, which may contain FODMAPs like garlic, onion, honey, etc.
– Check ingredients if buying canned fish like tuna, sardines or anchovies. Opt for fish packed in water or oil rather than sauces. Rinse canned fish before eating to remove excess liquid.
– Remove the skin from barramundi, snapper or other fish before cooking to lower FODMAP content.
– Grill, bake, broil, poach or pan fry fish using low FODMAP seasonings like lemon, herbs, pepper, etc. Avoid crumbing or battering fish which adds extra carbohydrates.
– Limit fish roe or eggs like salmon roe to about 1 tablespoon (15g) per sitting if following strict low FODMAP.
– Stick to about 4-6 ounces (110-170g) of salmon per meal, and avoid eating the skin which is higher in FODMAPs.
– Check seafood stock, fish sauce and oyster sauce for onion, garlic and other FODMAP ingredients. Opt for low FODMAP alternatives.
With these tips in mind, you can confidently enjoy the benefits of low FODMAP fish! Be sure to consult a qualified dietitian if you need individualized guidance on following the low FODMAP diet.
Simple low FODMAP fish recipes
Here are 3 simple, delicious recipes for preparing low FODMAP fish:
1. Lemon Baked Cod
Ingredients:
– 4 cod fillets (6 ounces each), skin removed
– 2 tbsp extra virgin olive oil
– Juice and zest of 1 lemon
– 1/4 cup chopped fresh parsley
– Salt and pepper to taste
Instructions:
1. Preheat oven to 400°F (200°C).
2. Place cod fillets in baking dish and drizzle with olive oil.
3. Squeeze lemon juice over cod and sprinkle with lemon zest, parsley, salt and pepper.
4. Bake for 12-15 minutes until fish flakes easily with a fork.
5. Serve with desired low FODMAP sides.
2. Broiled Salmon with Herbs
Ingredients:
– 4 salmon fillets (6 ounces each), skin removed
– 2 tbsp melted butter or ghee
– 2 tsp dried oregano
– 1 tsp dried basil
– 1 tsp dried thyme
– Lemon wedges for serving
Instructions:
1. Preheat broiler on high heat.
2. Place salmon fillets on a foil-lined baking sheet. Brush with melted butter or ghee.
3. In a small bowl, combine oregano, basil and thyme. Sprinkle seasoning evenly over salmon.
4. Broil salmon 8-10 minutes until just cooked through.
5. Serve salmon sprinkled with lemon juice.
3. Cajun Blackened Tilapia
Ingredients:
– 4 tilapia fillets (6 ounces each)
– 1 tbsp Cajun seasoning
– 1 tsp paprika
– 1 tbsp avocado oil or olive oil
– Lemon wedges for serving
Instructions:
1. In a small bowl, mix Cajun seasoning and paprika. Rub evenly over both sides of tilapia fillets.
2. Heat oil in large skillet over medium-high heat. When hot, add tilapia fillets.
3. Cook 3-4 minutes per side until fish flakes easily. Remove from pan.
4. Serve blackened tilapia with lemon wedges.
Which fish are safest for low FODMAP?
In summary, the following fish are safest choices on a low FODMAP diet:
– Anchovies, arctic char, bass, catfish, cod, flounder, grouper, haddock, halibut, mackerel, mahi mahi, monkfish, perch, pike, pollock, pomfret, red snapper, sardines, sole, striped bass, swordfish, tilapia, trout, tuna, turbot, and walleye.
– Salmon, white fish or oily fish are OK in moderate 4-6 ounce servings.
Limit or avoid:
– Fish skin and roe which are higher in FODMAPs
– Breaded or battered fish which adds extra carbs
– Canned fish packed in high FODMAP sauces
– Fish stock and sauces containing onion, garlic or other high FODMAP ingredients
Stick to fresh, plain fillets within recommended serving sizes. Grill, bake, broil or pan fry using low FODMAP seasonings. With these simple precautions, fish can be enjoyed freely on a low FODMAP diet!
Conclusion
Many types of fish are low in FODMAPs and can be enjoyed freely on a low FODMAP diet. The safest choices are fresh white fish or oily fish like salmon, sardines and anchovies within 4-6 ounce portions. Avoid fish skin or roe which are higher in FODMAPs, as well as breaded fish and high FODMAP sauces. Preparing fish simply with low FODMAP herbs, oils and spices allows you to gain the nutritional benefits of fish without aggravating your digestive system. Always consult a dietitian for individualized low FODMAP eating guidance.