Going Vegetarian Is the Most Cost-Effective Diet Choice, According to a New Study

As you’ve likely noticed, grocery prices have been steadily climbing for some time, with little indication that they’ll slow down any time soon — especially if you have eggs in your cart.

According to the U.S. Department of Agriculture (USDA), consumers spent an average of 11.2% of their disposable personal incomes on food in 2023. However, according to a new report by CouponBirds, your chosen diet may affect how much you spend — or save — on groceries. 

To figure out which diets offer the most significant savings and which cost the most, the team collected data between December 2024 and January 2025 on spending at three major grocery stores: Walmart, Kroger, and Target. It then filtered products based on six common dietary requirements: vegetarian, vegan, pescatarian, lactose-free, gluten-free, and halal. It then tallied pricing for a range of products across grocery store categories that were “representative of an average household grocery shop,” which totaled $232.17 for 45 common grocery goods.

But what happens when you swap out some of those goods for diet-specific options? Here’s what it found. 

Being a vegetarian is the most cost-effective option 

The study found that following a vegetarian diet — a diet choice made by 4% of the U.S. population —  is the most cost-effective option, saving consumers an average of $32.59 per weekly shop, or $130.36 per month, when compared to an unrestricted diet. The biggest savings came from swapping out more expensive animal-based products with plant-based substitutes. For example, consumers can save $6.31 when you swap salmon for tofu. 

Pescatarians can expect a slightly higher bill 

Next up is pescatarians, or those who avoid meat but still eat fish, who make up about 5% of the U.S. population. Their grocery bills are about 5.9% cheaper than unrestricted diets, saving an average of $13.75 per weekly shop. While seafood tends to be more expensive than some plant-based proteins, eliminating land-based meats still led to savings. 

Then, there’s the vegans 

Veganism, which excludes all animal products, is practiced by only about 1% of Americans. And while those who adhere to the diet spend less than those on unrestricted diets, the team found that their grocery savings are more modest at just 3.7% per week. That’s because vegan substitutes for dairy, bread, and snacks are often more expensive than vegetarian alternatives. In fact, 10 of the 45 items in the cart that were swapped for vegan alternatives were more expensive than the conventional counterparts. 

Halal was slightly more expensive than the standard list 

According to the study, 83% of Muslims say they only purchase halal-certified items. And as the second-largest religious group in the world, that’s a whole lot of shoppers. However, as the team found, purchasing halal-certified meat and avoiding pork products led to an average grocery increase of 4%, or $9.36 per week. The most expensive swap was generic chicken soup to Halal chicken soup, which was $9.60 more expensive. 

Lactose-free diets are even more costly 

The study noted that some 36% of Americans have lactose intolerance, leading many to go dairy-free. This, it added, drives up grocery costs significantly, specifically with lactose-free breads and pastries, which are notably more expensive than traditional versions, leading to a 5% overall price hike for an average cart. 

The most expensive diet is going gluten-free 

Going gluten-free is the most expensive diet of all, adding an extra $111.20 to monthly grocery bills, or a 12% overall increase. As the study noted, 16 substitutions had to be made for gluten-free shoppers, 13 of which were more expensive than their gluten equivalents. See all the swaps and where you can save at couponbirds.com.