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The flexitarian diet is one in which the goal is to eat plant-based as often as possible. However, unlike more restrictive vegetarian and vegan diets, the occasional inclusion of animal products—such as meat, fish, eggs, and dairy—is allowed.
Research suggests that plant-based diets offer numerous health benefits, from reduced cardiovascular disease to a lower risk of cancer, and even an increased lifespan. But is there a link between a flexitarian diet and longevity? Like taking longevity supplements, could eating less meat really help you live longer?
In this article, we'll examine the health benefits, potential drawbacks, and effect on lifespan of the flexitarian diet from a balanced perspective.
What Is a Flexitarian Diet?
“Flexitarian” is a relatively new term used to refer to those who only occasionally eat meat, fish, cheese, and eggs. Other commonly used terms include part-time vegetarian, casual vegetarian, or semi-vegetarian.
Strictly speaking, flexitarians are simply omnivores: people who eat foods of both plant and animal origin. The difference is that flexitarians focus mainly on fruits, vegetables, and other plant-based foods, and consciously aim to reduce their consumption of animal-derived ingredients.
What precisely constitutes a flexitarian diet varies depending on who you ask. One recent study in BMC Nutrition defined flexitarians as individuals who consume less than 50 g of meat per day (1). However, there are no strict rules regarding the frequency or amount of animal products you can consume—as the name suggests, it’s a fairly flexible approach to eating.
Typical Foods in a Flexitarian Diet
Flexitarians rely primarily on plant-based staples to meet their nutritional needs. Bread, pasta, rice, and potatoes provide carbohydrates, and fruits and vegetables add essential vitamins and fiber. Sources of protein can include beans, grains, lentils, and tofu, while avocados, nuts, and plant oils provide healthy fats. There is often an emphasis on wholefoods—however, processed foods aren’t necessarily excluded.
The key difference between flexitarianism and other plant-focused diets is the inclusion of animal products. Foods like red and white meats, fish, eggs, milk, cheese, yogurt, and gelatin can still be enjoyed in moderation. This can help flexitarian dieters avoid common pitfalls of plant-based diets, such as nutritional deficiencies.
The foods that make up the core of the flexitarian diet are largely up to the individual. Some flexitarians eat meat once a week, while others have only one meat-free day; some aim for a wholefood diet, whereas others focus only on reducing animal products. For many people, this adaptability is the main appeal of flexitarianism.
Health Benefits of a Flexitarian Diet
The health benefits of flexitarian and plant-focused diets have been thoroughly researched, and even more intensely debated. Below, we explore six key areas of human health that these diets may affect, and answer the question: does a flexitarian diet help you live longer?
1. Cardiovascular Health
Common cardiovascular health issues include heart disease, high blood pressure, and high cholesterol—all of which a flexitarian diet may help reduce the risk of or even reverse. Higher intake of fruits and vegetables, fiber, polyunsaturated fat, and lower intake of red and processed meat all contribute to a lower risk of these kinds of cardiovascular diseases (2). Plant protein consumption generally has an inverse association with heart disease, meaning that the more plant protein you eat, the less likely you are to develop heart problems (3).
There are several likely reasons for these positive health effects. For one, flexitarian diets are typically high in healthy fats and low in saturated fats, which are a key cause of heart problems. This is in contrast to red meat and processed meat in particular. Plant-forward diets also reduce inflammation and help your body absorb blood sugars, both of which also contribute to good heart health (2).
2. Weight Management
A key link between the flexitarian diet and living longer is its use as a weight-loss and weight-maintenance tool. This is similar to other plant-forward diets: vegetarians “have a lower prevalence of overweight and obesity [as] non-vegetarians from a similar background”.
The reasons behind this link also apply to flexitarian diets: they are typically higher in fiber, which leads to satiety, i.e. the feeling of being full. Also, while not exclusively, flexitarian diets often contain fewer calorie-dense processed foods (4).
In a more general sense, limiting your food intake in any way can be good for weight management. Flexitarianism can help you think more consciously about what you’re eating and encourage you to discuss your diet with your doctor—all of which can help you lose weight and keep it off.
3. Type 2 Diabetes Prevention and Management
Flexitarian diets may also help both reduce the risk of developing diabetes and manage type 2 diabetes.
Like other forms of diabetes management, a flexitarian diet can help by improving insulin sensitivity. According to the BMJ, substituting non-meat proteins for meat proteins reduces insulin resistance. In other words, plant proteins help your body process insulin as it should. So, by swapping out meat for plants, you could manage your diabetes as well as your weight (3).
Flexitarian diets also promote better blood sugar control. Increased consumption of fruits and vegetables, fiber, and healthy fats improve glycemic control (5).
4. Cancer Risk Reduction
Diets lower in red meat, like flexitarian diets, may even reduce your risk of developing certain types of cancer. The BMJ states that a “significant positive association” has been demonstrated between animal protein intake and some cancers, but also that intake of soy protein is associated with reduced incidence of breast cancer mortality. This may be because fermentation of plant proteins in the gut lowers toxic and carcinogenic metabolites such as ammonia; they can break down into bioactive peptides that have antioxidative and anti-inflammatory properties (3).
The link between meat consumption and cancer (specifically, colorectal cancer) is particularly strong with processed meat: the World Health Organization (WHO) classifies it as a Group 1 carcinogen, meaning “carcinogenic to humans”. Unprocessed red meat is in Group 2A, or “probably carcinogenic to humans”, as evidence from epidemiological studies is limited. Some experts disagree on the extent to which red meat causes cancer, and there is ongoing research and debate (6).
5. Gut Health
Plant-rich diets have been found to significantly improve gut health. The high fiber content found in legumes, grains, vegetables, and fruits helps regulate digestion; fiber takes longer to digest than simple sugars, so a diet rich in those foods should help maintain steady digestion and prevent spikes in blood sugar levels (4).
Another aspect of gut health is the microbiome. This is the collection of trillions of bacteria and other microbes that live in the gut, helping the body digest food. Having a varied diet encourages the growth of a diverse gut biome, which can improve:
Digestion of a variety of foods
Resistance to pathogens
Microbiome-gut-brain axis health (4)
Research into the gut-brain axis is still in its early stages, but there are suggestions that it may have unlikely influences on mood, cognitive function, stress, and more.
6. Mental Health and Well-being
Going flexitarian can improve mental health as well as physical health. Plant-based foods have potential mood-boosting effects, with a demonstrated “decrease in stress [and] anxiety” in studied vegan groups (4).
Also not to be underestimated is the satisfaction that comes from picking a diet that’s better for you, animals, and the planet. Without going overboard or making drastic changes, you can avoid the guilt of eating too much meat, and feel that you’re doing your part.
It is worth bearing in mind that “evidence for [the] cognitive and mental effects of a plant-based diet is still inconclusive”, however, as more research is needed (4).
Longevity and the Flexitarian Diet
Like research-backed longevity supplements (e.g. spermidine supplements, NMN and Resveratrol), diets that include more plant-based foods are also associated with increased life expectancy. In other words, there is an established link between adopting a flexitarian diet and living longer.
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A 2022 study found that the optimal diet for longevity is one that has a higher intake of whole grains, legumes, fish, fruits, vegetables, includes a handful of nuts, and is lower in red and processed meat, sugar-sweetened drinks, and refined grains (7). This is noticeably similar to the ‘blue zone’ diet—a diet based on the lifestyles of people who live in areas with high life expectancies, such as Ikaria, Greece and Sardinia, Italy (8).
The potential mechanisms by which a flexitarian diet extends the lifespan are fairly well established: improvement of cardiovascular health, reduction in incidence and severity of certain high-risk cancers, weight management, and more.
On a molecular level, blood sugar is better controlled, a better micronutrient balance can be achieved, gut health can be improved, and—as with fasting—inflammation and oxidative stress are reduced.
Environmental Impact
Besides being good for your health, plant-focused diets are projected to have less environmental impact than diets higher in animal products (9). Flexitarianism could benefit the planet through:
Reducing your carbon footprint. Progressively replacing animal products with plant-based foods could lead to large reductions in greenhouse gas emissions. Replacing 25% of animal-source foods results in a 20% reduction, while a 100% replacement would result in an 84% reduction.
Conserving water. Agriculture uses 70% of all freshwater resources globally. Making thoughtful changes—e.g. cutting out beef, but also avoiding resource-intensive foods like almonds—could significantly reduce the water usage your diet is responsible for.
Land use efficiency. Replacement of animal products with plant based foods could reduce cropland use by “12% in upper-middle-income countries and 29% in high-income countries”.
So, small changes to your diet can contribute to big changes globally.
How to Adopt a Flexitarian Diet
Becoming a flexitarian is really as simple as making a conscious effort to reduce the amount of meat, fish, eggs, and dairy you eat. As there are no set rules or limits on animal product consumption, it’s less strict than diets such as vegetarianism or veganism.
Getting Started
The key to adopting a flexitarian diet is to start small, and make changes at a pace that suits you.
Consider beginning with one meat-free day per week, e.g. “Meatless Mondays”. You can then gradually increase the number of meat-free days as you become more comfortable. Alternatively, you could start by having one plant-based meal each day, and work your way up to two or three.
Many new flexitarians find it easier to stick with familiar dishes at first, only replacing animal proteins with vegetarian alternatives. This could be as simple as making chili with beans instead of ground beef, or topping your pizza with mushrooms rather than pepperoni.
Keeping your refrigerator and pantry stocked with versatile plant-based options and making a list of easy meatless meal ideas can help you to stay on track.
Sample Meal Plan
When it comes to flexitarian meal planning, try to aim for a healthy balance of fat, protein, and carbohydrates, and incorporate plant-based options wherever possible. Here is an example meal plan to get you started:
Remember that your calorie needs may be higher or lower than others’. You should also ensure your diet is sufficient in essential vitamins, minerals, and electrolytes.
Potential Challenges and Solutions
Though it’s clear that there are many potential benefits, a flexitarian diet isn’t without its challenges.
Like other diets that limit animal product intake, flexitarians can sometimes find it difficult to get enough vitamin B12 and other micronutrients (9). Fortunately, this can be corrected with thoughtful meal planning or supplementation.
Flexitarianism can also make dining out difficult, or even cause awkward social interactions. Navigating menus and finding new favorites at your usual restaurant can be a little tricky, and sometimes family and friends may struggle to accommodate your dietary restrictions. As you and your loved ones grow more accustomed to your new way of eating, however, you’ll find these challenges easier to overcome.
Is Flexitarianism Right for Everyone?
Flexitarianism is generally considered a healthy approach to eating, but it’s important to be aware of potential contraindications. For example, it may not be appropriate for certain individuals with digestive issues, eating disorders, iron deficiency anemia, or conditions that affect nutrient absorption. Children and pregnant people should be particularly careful to make sure they’re getting the nutrients they need.
It’s also worth noting that not all flexitarian diets are necessarily healthy. You can be flexitarian, vegetarian, or even vegan, and still have a diet high in carbohydrates, saturated fats, and processed foods. Before making any significant changes, it’s always best to consult your healthcare provider.
To Summarize
For most people, a flexitarian diet can offer numerous health benefits—and may even extend your lifespan. Several studies have linked diets lower in animal products and higher in plant proteins with improved heart health, better weight management, lower risk of diabetes and cancer, and increased longevity. Not to mention, it’s a great way to reduce the environmental impact of the food you eat.
The key to successful flexitarianism lies in personalization: making conscious choices to include more plant-based meals in a way that works for you. With mindful planning and a balanced approach, you can make gradual, sustainable changes to improve your health and overall well-being.