Eating more plant-based foods is often seen as another wellness trend, something to try for a week and forget. But when chronic illnesses start creeping in, from high blood pressure to type 2 diabetes, the impact of what we eat becomes harder to ignore.

Sandhya Subedi, a nutritionist and food educator with a Master’s degree in Food Science for Nutrition from Mahidol University, Thailand, unpacks the nuances of everyday eating through her platform Sataahar.

In this conversation with the Post’s Aarya Chand, she explains that a well-planned plant-based diet prevents disease, reduces inflammation, and promotes overall health.

What is a plant-based diet?

A plant-based diet does not have a uniform definition. For vegans, it means consuming only plant-derived foods, excluding meat, dairy, eggs or honey. However, a diet pattern that chooses a greater proportion of foods from plants such as whole grains, legumes, nuts, seeds, fruits and vegetables and less from meat and dairy is called a plant-based diet.

Which specific nutrients are found in plant-based foods that help protect against illness?

Various specific nutrients in plant-based foods contribute to protection against illness. The most well-recognised include dietary fibre, monounsaturated and polyunsaturated fats, and various phytochemicals such as carotenoids and polyphenols. These components play key roles in supporting metabolic health, reducing inflammation, and protecting against chronic diseases.

Is a plant-based diet safe and beneficial for people of all ages and health conditions?

Yes. Like any dietary pattern, plant-based diets require proper planning to ensure nutritional adequacy. If poorly designed, deficiencies can occur in any diet, plant-based or otherwise.

According to the American Dietetic Association and Dietitians of Canada, appropriately planned vegetarian and vegan diets are nutritionally adequate and can help prevent and treat certain diseases.

The Italian Society of Human Nutrition and Dietitians of Canada have endorsed similar positions, affirming that vegetarian and vegan diets are suitable for all life stages.

However, formal position papers or national guidelines are lacking in many countries for vegan diets that exclude animal products entirely. For instance, Nepal does not have official recommendations or long-term local research on vegetarian or vegan diets. Despite this, existing international evidence and the general consensus among plant-based dietitians suggest that a well-planned vegan diet can be safe and adequate for children and during pregnancy, particularly when followed with appropriate guidance.

Can a plant-based diet help reduce inflammation in the body?

Inflammation is often discussed in health contexts today, but it’s important to distinguish between types. Acute inflammation is a short-term, necessary response to injury or infection that helps the body heal. Chronic inflammation, on the other hand, is a long-term, low-grade inflammatory state that is associated with various chronic diseases and is considered problematic.

Plant-based diets have been associated with reductions in chronic inflammation. For example, a meta-analysis of 29 intervention trials found that plant-based diets reduced markers of obesity-related inflammation. Other studies have reported reductions in inflammatory markers and atherogenic lipoproteins within a few weeks of following a defined plant-based diet and improvements in metabolic markers in overweight individuals following a plant-based diet over 16 weeks. These effects are thought to be due in part to anti-inflammatory and gut-supportive compounds found in plant foods.

How effective is a plant-based diet for maintaining a healthy weight and avoiding obesity-related conditions?

Research has shown that plant-based diets can be effective in maintaining a healthy weight and reducing the risk of obesity. Minimally processed plant foods tend to have lower energy density and higher nutrient content, which can support weight management. Dietary approaches like ‘volume eating,’ often recommended by registered dietitians, emphasise high-fiber foods; primarily from plant sources that promote satiety without excessive calorie intake.

This effect has been observed across various age groups, including both children and adults. In individuals with type 2 diabetes, plant-based diets have been associated with reductions in waist circumference, body mass index (BMI), and overall body weight. A more recent review also supports the use of plant-based diets for obesity management by highlighting their potential to improve weight outcomes without restrictive calorie counting.

What role does a plant-based diet play in preventing chronic diseases like heart disease, type 2 diabetes, and high blood pressure?

Over the past two decades, numerous clinical trials and observational studies have examined the relationship between plant-based diets and chronic diseases such as heart disease, type 2 diabetes, and high blood pressure. The findings suggest that plant-based dietary patterns are associated with a reduced risk of these conditions.

Research has shown that individuals following plant-based diets tend to have improved blood lipid profiles, including lower total and LDL cholesterol levels, lower blood pressure, and lower body mass index (BMI). Additionally, plant-based diets have been linked to a lower risk of certain cancers, including colorectal and breast cancer.

How soon might someone see health benefits after switching to a plant-based diet?

There is no strict switch to a plant-based diet unless someone follows a completely animal-based (carnivore) diet. For most people, adopting a plant-based diet simply involves increasing the proportion of plant foods in their meals. How this transition happens—gradually or more quickly—depends on individual preferences and how balanced the overall diet is.

It’s important to note that not all plant-based foods are necessarily healthy. Highly processed items like sugar-sweetened beverages, cookies, or snacks made with refined ingredients can be plant-based but offer little nutritional value. As said earlier, a health-supportive plant-based diet focuses on whole, minimally processed foods such as vegetables, legumes, whole grains, nuts, and seeds.

The benefits of shifting toward plant-based eating can appear relatively quickly. For example, increasing fibre intake can help relieve constipation within days. Improvements in cholesterol levels may take weeks to months, often combined with other lifestyle changes. While there is no exact timeline for everyone, increasing the intake of plant foods like vegetables, nuts, and seeds supports short—and long-term health.