It’s widely known that adopting a well-balanced plant-based diet brings numerous health benefits. Increasing fruit and vegetable intake is undeniably a wise choice. However, the effects of transitioning to a vegetarian diet may not be entirely intuitive. While such a diet can enhance sleep, heart health, and the microbiome, it may also lead to reduced energy levels and potential nutrient gaps.
If you’re contemplating eliminating meat, poultry, and fish from your diet, here’s a likely response from your body.
Your Energy
Switching to a nutritious plant-rich diet can boost energy by replacing processed animal products with whole foods like fruits, vegetables, whole grains, nuts, and seeds. However, eliminating animal products may lead to nutrient gaps. For instance, iron from plant sources like spinach and soybeans (non-heme iron) is less bioavailable than that from animals, according to the U.S. National Library of Medicine.
Adequate iron intake is crucial as it facilitates oxygen transport for energy production, and low iron levels can cause fatigue, hair loss, dizziness, weakness, and other symptoms. Vegetarians may have lower iron stores than non-vegetarians, requiring almost double the recommended intake.
This is especially important for menstruating women or those with iron-deficiency anemia. Non-heme iron sources include beans, chickpeas, apricots, potatoes, wheat germ, and seeds.
Your Gut Health
If you sense that gut health is a predominant concern in the wellness realm, you’re accurate. The composition of your gut microbiome significantly impacts health, with bacteria in the large intestine playing a crucial role, as stated in a July 2019 article in “Nutrients.”
“Meat, especially red and processed meats, can induce gut inflammation, disrupting beneficial bacteria and causing digestive issues like constipation and bloating.”
While our individualized microbiomes are acknowledged, lifestyle choices, including diet, possess the potential to influence our microbiome positively or negatively.
“Meat, especially red and processed meats, can induce gut inflammation, disrupting beneficial bacteria and causing digestive issues like constipation and bloating,” notes Dr. Pena. Conversely, embracing a vegetable-rich diet often produces the opposite effect. Vegetarian and Mediterranean-style diets have been linked to favorable changes in the gut microbiome, as suggested by a September 2018 study in “The Journal of Nutrition.”
Removing meat and fish from your diet may lead to an increased consumption of anti-inflammatory plant foods, many rich in gut-friendly prebiotics and probiotics.
To recap, prebiotics are indigestible carbohydrates supporting good gut bacteria, found in fruits (like bananas and apples), vegetables, and whole grains. Probiotics are live microbes present in fermented foods such as kefir, yogurt, sauerkraut, and supplements.
Switching to a vegetarian diet may yield noticeable digestive improvements within weeks, according to Dr. Pena.
Your Sleep and Mood
Increasing plant consumption may contribute to improved sleep quality. According to DJ Blatner, RDN, author of “The Flexitarian Diet,” the high isoflavone content in plant-rich diets, notably found in soybeans, is linked to enhanced sleep quality and reduced depressive symptoms, as indicated by a December 2015 study in “Nutrition Journal.”
Isoflavones are also recognized as a well-tolerated option for managing depression, as suggested by a December 2017 study in “Menopause.”
Expanding your diet to include a variety of fruits and vegetables beyond soy can potentially uplift your mood. Diets primarily consisting of meat, poultry, and fish may contain high levels of arachidonic acid, an inflammatory omega-6 fat. Research indicates that elevated arachidonic acid intake can induce brain changes that disrupt mood.
In contrast, vegetarian diets, with a higher carbohydrate-to-protein ratio compared to omnivorous diets, facilitate more tryptophan (an amino acid) entering the brain, where it converts to mood-boosting serotonin, according to research in the book “Vegetarian and Plant-Based Diets in Health and Disease Prevention.” It’s like having a happy meal plan!
Your Weight
Before transitioning to a plant-based diet for weight loss, it’s important to note that any change in your meal plan can lead to mild to moderate weight loss, depending on the duration of adherence, says Fraga.
In essence, there’s no necessity to eliminate animal products solely for the purpose of slimming down. However, adopting a plant-filled diet may yield positive changes on the scale. A June 2017 meta-analysis in “Critical Reviews in Food Science and Nutrition” found that compared to omnivores, vegetarians exhibited significantly reduced body mass index (BMI).
Furthermore, individuals following a plant-based meal plan may experience weight loss due to the lower caloric content in lean protein and plant-based food choices. Fraga notes, “Meats and animal-based foods can be more caloric due to their fat content.”
Your Heart Health
“Some of the benefits of eliminating meat and other sources of animal fat include reduced cholesterol levels and decreased inflammation in the body,” notes Dr. Pena. This, in turn, can lead to less plaque buildup and a reduction in heart-related issues, with improvements in cholesterol levels expected around the two- to three-month mark.
Following a vegetarian meal plan is associated with a 40% decreased risk of heart disease, according to a May 2018 study in the journal “Progress in Cardiovascular Diseases.” A February 2020 study in “Neurology” found that a vegetarian diet rich in nuts, vegetables, and soy is linked to a lowered risk of total, ischemic, and hemorrhagic strokes in individuals over 50.
Plant protein is linked to a lower risk of all-cause and heart disease mortality. Replacing animal protein with plant sources is associated with longevity, as per a July 2020 “BMJ” meta-analysis.
Additionally, a February 2020 study in the “Journal of the American College of Cardiology” highlighted TMAO, a metabolite linked to heart disease, noting that adopting a vegetarian or vegan diet can lower TMAO production, potentially reducing the risk of heart disease.
It’s important to note that eliminating fish from the diet is a different consideration, mainly due to omega-3 fatty acids. Omega-3s may benefit heart health by reducing triglycerides, lowering blood pressure, decreasing blood clotting and irregular heartbeats, and lowering the risk of stroke and heart failure.
Dr. Pena advises, “Eating at least two servings a week of fish, particularly those rich in omega-3 fatty acids, appears to reduce the risk of heart disease, especially sudden cardiac death.” While concerns exist regarding mercury and antibiotic content in certain fish types, seafood isn’t necessarily detrimental to heart health. In fact, avoiding seafood may result in missing out on critical heart-healthy nutrients.
Your Nutrition Status
Although nutrients such as iron are found in both plant and animal foods, certain crucial vitamins are exclusive to animal products.
Eliminating meat, poultry, and fish from the diet may lead to deficiencies if one doesn’t maintain a varied diet and supplement appropriately.
“Vitamin B12 deficiency is common in a vegan or vegetarian diet,” notes Fraga. This is because B12 is naturally found only in animal foods like clams, trout, beef, salmon, and tuna. Some plant-based items, such as nutritional yeast, are fortified with the vitamin.
Omega-3s and zinc are two additional nutrients that may be lacking in a plant-based meal plan. “Omega-3 fatty acids are crucial for maintaining heart health,” adds Fraga.
The encouraging news is that, while fish and eggs are commonly considered rich sources of omega-3s, these essential fats can also be found in plant-based options like chia seeds, flaxseeds, walnuts, and hemp seeds.
The Takeaway
Eliminating animal products such as meat, poultry, and fish from your diet can yield impressive health benefits, including improved heart health and sleep quality, along with positive environmental impacts.
However, transitioning to a vegetarian diet may pose potential drawbacks, particularly if meals are not well-balanced, leading to deficiencies in critical vitamins and minerals.
The timeline for these changes varies, as stated by Dr. Pena. Immediate effects on digestion may be noticed within weeks, while iron deficiencies could emerge within several months without adequate replacement. Changes in weight and cholesterol levels may take at least two to three months to become evident.
If contemplating a switch to a vegetarian diet, it is advisable to consult with your doctor or a registered dietitian to ensure a safe and sustainable modification of your meal plan.