The Vegan Diet and Weight Loss

In the U.S., only about 1% of people follow a strictly vegan diet, according to a 2023 Gallup poll. However, many others say they have considered or tried it or are at least trending away from animal-based foods.

Consider these statistics from Wakefield Research:

• In 2023, 42% of Americans reported making a New Year’s resolution related to eating more plant-based foods

• 32% have never tried substituting plant-based alternatives to meat or dairy in their diets

• 34% have expressed some interest in going vegan

People choose to follow the vegan diet for various reasons ranging from health benefits to concerns about animal cruelty to reducing their carbon footprint. One reason you may encounter patients is the desire to lose weight or overcome obesity.

The American College of Lifestyle Medicine says, “Individuals consuming more plant-based diets have lower rates of overweight and obesity than those whose diets include or emphasize meat and refined foods.” Numerous articles directed at the patient audience repeat this claim.

In your practice, you may have encountered patients with questions about the potential health benefits of a vegan diet. Some people wonder if veganism can really help them lose weight. It may benefit you to understand more about the vegan diet and how to answer their inquiries.

What is a Vegan Diet?

The vegan diet is a type of vegetarian diet, but in addition to meats and fish, it also eliminates eggs, dairy, and all other animal products. These include honey, gelatin, certain food colorings, some types of alcohol, and all other animal products. It is sometimes referred to as a plant-based diet (PBD).

Animal proteins are ideally replaced with other protein sources, such as legumes, nuts, and certain high-protein grains and vegetables. Additionally, there are now plentiful non-dairy options like coconut, soy, oat, hemp, and almond products that can replace milk, cheese, or butter.

Contrary to stereotypes, veganism does not mean eating only salad. Nor does it necessarily mean avoiding gluten or eating only raw foods, although both choices can go along with veganism.

Should you Encourage Patients to Adopt a Vegan Diet?

Limiting intake of saturated fats such as those found in meat and dairy products certainly confers health benefits, as we know.

However, is it necessary to eliminate them entirely to achieve weight loss? Of course not.

It’s a good idea to first understand a patient’s reason for considering a vegan diet. If it aligns with their values and may also help them lose weight, then you can advise them on how to make the transition successfully.

Like other diets, veganism requires planning and food preparation. Also, as with any nutritional plan, weight loss depends on overall calorie reduction along with additional lifestyle changes. Because, in general, a vegan diet means fewer calories, less saturated fat, and more fiber, it tends to be healthier overall. That makes it a viable path to weight loss for many people.

A literature review published in Frontiers in Nutrition looked at the effects of a PBD on obesity in the short term (while stating that longer-term studies are needed).

The authors summarized, “PBD is a beneficial approach to improving health, particularly in obese patients. Benefits include weight loss, improved cardiovascular health, lower blood pressure, and improved glucose metabolism.”

What to Watch Out For With a Vegan Diet

When adopting a vegan diet, it’s important to ensure that the person maintains a balance of all key nutrients. While the vegan diet can be well-balanced, there are certain nutrients that require extra attention. These include:

• Protein

• Vitamin B12

• Calcium and vitamin D

• Zinc

These challenges can be overcome with adequate intake of—for example—dark green, leafy vegetables, complete proteins such as quinoa, and legumes. The person will need to plan carefully when it comes to grocery shopping, meal planning, and especially when dining out, to make sure each meal contains an adequate amount of key nutrients.

Other risks to someone switching to a vegan diet may include:

• Over-reliance on carbohydrates or processed foods

• Gaps in knowledge for planning and preparation

• Potential energy imbalances

• Social and practical challenges

When advising patients on the vegan diet, clinicians should take an individualized approach, ensure nutritional adequacy, and help address any potential risks or deficiencies associated with the diet. It is important to regularly monitor nutrient levels and overall health to ensure optimal outcomes of the vegan diet.

Tips for Losing Weight on a Vegan Diet

When considering the vegan diet in the context of obesity, several expert tips can guide individuals toward successful weight management:

Focus on Whole Foods

Encourage individuals to prioritize whole, unprocessed plant-based foods such as fruits, vegetables, whole grains, legumes, nuts, and seeds.

These nutrient-dense options are rich in fiber, vitamins, and minerals and can support weight loss and overall health.

Manage Portions

Emphasize the importance of portion control, even when consuming plant-based foods.

While vegan options can be healthy, overeating can hinder weight management goals. Encourage patients to practice mindful eating and to pay attention to hunger and fullness cues.

The caloric intake for someone with obesity on a vegan diet will vary depending on age, gender, weight, height, activity level, and individual goals.

In general, a safe and effective weight loss approach is to create a calorie deficit of approximately 500-1,000 calories per day. This gradual calorie reduction can lead to a sustainable weight loss of about 1-2 pounds per week.

Optimize Protein Intake

Ensure adequate protein consumption by incorporating various plant-based protein sources such as legumes, tofu, tempeh, seitan, and plant-based protein powders. Protein aids in satiety, preserves lean muscle mass, and supports weight loss efforts.

Understand the Role of Fats

Educate individuals about incorporating healthy fats into their diet in moderation, such as avocados, nuts, seeds, and plant-based oils. These fats provide satiety and contribute to overall satisfaction in meals.

Balance Macronutrients

Encourage a balanced macronutrient distribution in appropriate proportions, including complex carbohydrates, proteins, and healthy fats. This balance supports sustained energy levels, promotes fullness, and aids in weight management.

Vegans are particularly at risk of not eating enough of three essential amino acids: lysine, methionine, and tryptophan. Remember to encourage vegan patients to eat a variety of different plant foods, including:

• Lysine sources – avocados, wheat germ, and legumes

• Methionine sources – wheat, wheat germ, millet, barley, brown rice, corn, kamut, oats, rye, sorghum, teff, triticale, and quinoa

• Tryptophan sources – seeds, nuts, legumes, and grains

Plant foods also do not contain the following three conditionally essential molecules made from amino acids: creatine, carnitine, and taurine. While these molecules can be produced in the body, production can be impaired by increased physiologic stress (including pregnancy, significant and sustained physical exertion, and chronic medical conditions).

Consider supplementation in these cases.

Consider Snacks as Part of the Plan

Promote healthy snacking habits by suggesting fresh fruits, raw vegetables, nuts, or homemade plant-based snacks. Encourage patients to be aware of portion sizes and choose nutrient-dense snacks as part of their daily calorie intake.

Avoid Ultra-Processed Plant-Based Foods

Remember that not all vegan products are healthy. Packaged foods, including many cookies, chips, and meat substitutes, can be vegan but still ultra-processed.

The key to weight loss is still to eat mostly high-fiber, whole or minimally processed, less calorie-dense plant foods in moderation instead of only reducing calories.

Prioritize Physical Activity

Emphasize the importance of regular physical activity along with a vegan diet for weight management. Encourage patients to engage in activities they enjoy, whether it’s walking, cycling, dancing, or participating in fitness classes. Also emphasize the importance of strength and resistance activities at least twice a week. This will help maintain lean muscle mass while losing weight.

Other Health Benefits of a Vegan Diet

Beyond obesity, the vegan diet offers a wide range of health benefits that have been extensively researched and documented.

Firstly, it tends to be rich in fiber, which aids in digestion, promotes a healthy gut microbiome, and helps regulate blood sugar levels. A well-planned vegan diet is typically lower in saturated fat and cholesterol, improving heart health and reducing the risk of cardiovascular diseases.

The abundance of fruits, vegetables, whole grains, and legumes in a vegan diet provides a wealth of vitamins, minerals, antioxidants, and phytochemicals that support a robust immune system, reduce inflammation, and protect against chronic diseases such as type 2 diabetes, certain cancers, and age-related macular degeneration.

The vegan diet emphasis on whole, plant-based foods provides numerous health benefits, making it a promising approach for weight loss and overall well-being.

By adopting a vegan lifestyle, individuals can benefit from a diet that is naturally low in calorie density, rich in fiber, and devoid of harmful saturated fats and cholesterol. The abundance of fruits, vegetables, whole grains, legumes, nuts, and seeds offers diverse nutrients, antioxidants, and phytochemicals that support weight loss, improve metabolic health, and reduce the risk of chronic diseases.

However, it is crucial to approach the vegan diet for obesity treatment with careful planning, considering individual nutrient requirements for each patient.

With its potential to promote sustainable weight loss, improve health markers, and contribute to a more sustainable world, the vegan diet presents a compelling path towards combating obesity and fostering holistic well-being.

Learn more about nutrition as it relates to obesity by visiting the Obesity Medicine Association’s Nutrition Therapy On Demand course.

Consider joining a network of colleagues working in obesity medicine by visiting our membership page.