10 Benefits of Becoming Vegetarian

Benefits of Becoming Vegetarian (What the Research Actually Shows)

Going vegetarian isn’t a magic reset button. It’s a shift in eating pattern that, if done well, tends to lower cardiovascular risk, improve weight regulation, and reduce environmental footprint. The evidence is stronger for some claims than others. This piece walks through the ones that hold up.

To be clear about the frame: “vegetarian” here means lacto-ovo (dairy and eggs allowed, no meat/poultry/fish), which is what most Western studies measure. Vegan and semi-vegetarian patterns show similar directional benefits, sometimes stronger and sometimes weaker.

What’s on This Page

• Lower cardiovascular risk
• Weight loss and body composition
• Better blood sugar and diabetes risk
• Reduced risk of certain cancers
• Higher fiber, better digestion
• Longevity and mortality
• Environmental impact
• Lower grocery cost
• What to plan for (supplements and nutrients)
• FAQ

Lower Cardiovascular Risk

This is the strongest, best-documented benefit. A 2019 systematic review and meta-analysis by Kim and colleagues, published in the Journal of the American Heart Association (PMID 31284814 / 31504070 for the vegetarian outcomes review), pooled dozens of cohort studies and found vegetarians had a 25 percent lower risk of ischemic heart disease and 8 percent lower incidence of cancer overall compared with non-vegetarians.

Why it works: vegetarians tend to eat less saturated fat, more fiber, more plant polyphenols, and more potassium. All of that pushes LDL cholesterol down, blood pressure down, and inflammation markers down. The 2016 Academy of Nutrition and Dietetics position paper on vegetarian diets summarizes the mechanism the same way.

Weight Loss and Body Composition

Barnard and colleagues’ 2015 meta-analysis in the Journal of the Academy of Nutrition and Dietetics (PMID 25592014) pooled 15 randomized controlled trials of vegetarian vs conventional diets. Vegetarian dieters lost 2 kg more, on average, than those on omnivorous comparison diets. Vegan dieters lost slightly more than lacto-ovo vegetarians. The effect held even without a calorie-restriction instruction, which suggests the eating pattern itself lowers calorie density.

A few reasons this happens:

• Plant foods are typically lower in calorie density (more volume per calorie)
• Higher fiber increases satiety and slows gastric emptying
• Removing meat often means removing the most calorie-dense ultra-processed products (bacon, deli meats, fast food)

Caveat: a vegetarian diet built on pasta, cheese, and cookies won’t produce these results. Whole-food vegetarianism is doing the work.

Better Blood Sugar and Type 2 Diabetes Risk

Adventist Health Study 2, one of the largest cohorts tracking vegetarians, found that vegetarians had roughly half the type 2 diabetes prevalence of non-vegetarians. Vegans had the lowest rates; lacto-ovo vegetarians and pescatarians were in between; non-vegetarians had the highest.

For people who already have type 2 diabetes, plant-based dietary patterns are supported by the American Diabetes Association’s 2019 nutrition consensus report as one of several effective options for glycemic control and cardiovascular risk reduction. As always, medication adjustments should happen with a physician.

Reduced Risk of Certain Cancers

The World Health Organization’s International Agency for Research on Cancer (IARC) classified processed meat as a Group 1 carcinogen and red meat as a Group 2A (probable carcinogen) in 2015, largely based on colorectal cancer evidence. Vegetarians, by definition, avoid both.

The Kim 2019 review found an 8 percent lower cancer incidence overall for vegetarians. The strongest signal is for colorectal cancer. Evidence for other cancers (breast, prostate, lung) is weaker or inconsistent.

Higher Fiber, Better Digestion

The average American eats about 15 g of fiber daily, well below the USDA recommendation of 25 g for women and 38 g for men. Vegetarians typically hit 30 to 40 g simply from beans, whole grains, and vegetables. That extra fiber:

• Feeds gut bacteria that produce short-chain fatty acids (linked to reduced inflammation)
• Keeps bowel movements regular, reducing constipation
• Lowers LDL cholesterol (soluble fiber binds bile acids)
• Blunts post-meal glucose spikes

Longevity and Mortality

Adventist Health Study 2, tracking over 73,000 Seventh-day Adventists, found vegetarians had a 12 percent lower all-cause mortality than non-vegetarians over a six-year follow-up. Some of that is diet, some is that this population also tends toward low alcohol, no smoking, and regular exercise, so isolating pure diet effect is difficult.

Still, the pattern is consistent across multiple large cohorts (EPIC-Oxford, Adventist Health, and others).

Environmental Impact

Meat production accounts for a large share of global greenhouse gas emissions, land use, and freshwater consumption. A 2018 Poore & Nemecek study in Science estimated that switching from a meat-heavy diet to a vegetarian or vegan one could reduce an individual’s food-related carbon footprint by roughly 50 percent.

Environmental impact varies within vegetarianism too: dairy cattle also contribute meaningful emissions. Vegans typically have the lowest food footprint; vegetarians heavy on cheese sit closer to omnivores on emissions per calorie.

Lower Grocery Cost

Meat is usually the most expensive line item in a grocery budget. Substituting beans, lentils, eggs, tofu, and grains typically drops weekly grocery spending by 20 to 40 percent, depending on where you shop and how much prepared food you rely on. Ultra-processed vegetarian food (fake meats, prepared entrees) narrows that gap.

What to Plan for (Supplements and Nutrients)

The benefits above only materialize if the diet is nutritionally complete. Vegetarians should watch:

NIH Office of Dietary Supplements recommends 2.4 mcg of B12 daily for adults. Menstruating women need 18 mg of iron daily; vegetarian women should aim higher (roughly 1.8x the RDA) because non-heme iron absorbs less efficiently.

FAQ

Will I lose weight going vegetarian?

Probably, though not automatically. Meta-analyses show an average 2 kg advantage over omnivorous diets in short-term trials. A vegetarian diet built on pasta, cheese, and processed food won’t produce the same result.

How do vegetarians get enough protein?

Eggs, dairy, lentils, beans, tofu, tempeh, quinoa, nuts, and Greek yogurt. It’s easier than the meat-eating world suggests. Most vegetarians hit or exceed protein RDAs without any effort.

Does a vegetarian diet really lower heart disease risk?

Yes. The strongest, most consistent finding across vegetarian nutrition research is a 20 to 25 percent lower ischemic heart disease risk. Lower saturated fat, higher fiber, higher potassium, and better weight regulation all contribute.

Do all vegetarians need supplements?

B12 is the one to plan for, especially if you’re vegan or eat few dairy and eggs. Iron for menstruating women. Vitamin D and omega-3 for many people regardless of diet.

How should I transition from omnivore to vegetarian?

Gradual usually beats overnight. Meatless Monday is a classic starter. Add one plant-forward meal per week, then two, then all. Replace, don’t remove: swap ground beef for lentils, chicken for chickpeas, so your plate doesn’t feel empty.

Can you build muscle on a vegetarian diet?

Yes. Adequate protein (roughly 1.6 to 2.2 g per kg body weight for strength training) plus resistance training builds muscle. Many pro athletes are vegetarian or vegan. Focus on protein-dense plant foods, plus eggs and dairy if you eat them.

What are the drawbacks?

Nutrient gaps if not planned well (B12, iron, omega-3). Social friction at restaurants and family meals. Higher grocery cost for prepared vegetarian products (though whole-food vegetarianism is usually cheaper than meat-based).

Related Reading

• 7-day vegetarian diet plan
• Vegetarian diet grocery list
• Vegetarian protein sources
• Foods vegetarians can’t eat