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Plant-Based Diets and Health (An Independent Meta-Analysis of Intervention Trials)

Updated: Jan 4


On the back of my independent meta-analysis investigating the relationship between low carbohydrate/ketogenic diets and health markers in intervention trials, I now give you my independent meta-analysis investigating the relationship between plant-based diets and health markers in intervention trials.


The plant-based community has just as much of a tendency to cherry-pick study results as any other diet community wherein certainty is low and guruism is high. This independent meta-analysis is my attempt to add some clarity to online and academic discourse regarding plant-based diets and health—do these types of diets actually live up to the hype?


It is my hope that this blog article might serve as an educational resource for anyone aiming to learn about how plant-based diets could relate to health. As well as whether or not those health outcomes are independent of duration or weight loss. There are many supposed effects of plant-based that many of us may just take for granted, such as reductions in low density lipoprotein cholesterol or lower inflammatory markers. However, it is unclear whether or not these effects, if they exist at all, are independent of weight loss or the duration of time spent on the diet.


It is also true that some of us may expect negative things to happen on a plant-based diet, like elevated triglycerides or higher blood glucose. It is likewise unclear whether or not these effects are independent of weight loss or the total amount of time spent on the diet. Hopefully the data below will help inform some of these debates and discussions, as well as help rectify any potential misconceptions one might have.


I will also not be including any interpretations of any of the data. I am not a health professional of any kind, and it is not my job to interpret this data. I searched for it. I collated it. And now it's yours.


Results will be stratified six ways:

  1. Plant-based diets compared to control.

  2. Plant-based diets compared to baseline.

  3. Plant-based diets stratified by duration, compared to control.

  4. Plant-based diets stratified by duration, compared to baseline.

  5. Plant-based diets stratified by weight loss, compared to control.

  6. Plant-based diets stratified by weight loss, compared to baseline.

Inclusion Criteria:


Due to the fact that there is no clear, standardized definition of a "plant-based" diet in the literature, the inclusion criteria for this meta-analysis was difficult to formulate. An obvious correlate for a diet that emphasizes plant foods might be dietary cholesterol (due to it only being found in animal foods). However, no trial actually achieved a zero-cholesterol diet in the intervention group, and some diets may be higher in dietary cholesterol despite a significant overall decrease in animal food consumption. For example, a diet that substitutes 150 kcal of eggs for 1000 kcal of assorted animal products could potentially have the exact same dietary cholesterol yield overall, despite the fact that one diet may be significantly more plant-based than the other diet.


A minority of studies divulged the percentage of calories from either animal foods or non-animal foods in the intervention diets. So, such criteria would have narrowed the range of eligible trials to an unacceptable degree. In order to insulate myself from criticisms to the greatest degree possible, I let the literature itself dictate my inclusion criteria. If the experimental diet used in an intervention trial had been referenced as "plant-based" or "vegan" in the literature (either in a meta-analysis, narrative review, systematic review, trial paper, etc.), I invoked the if-it-is-good-enough-for-them-it-is-good-enough-for-me principle, and included them. Don't fucking @ me, bro.


Disclaimer:

  • This is not a peer-reviewed publication. This blog article is for educational and/or entertainment purposes only. This blog article is not an academic reference, nor does it stand in place of current or future peer reviewed, academic research into plant-based diets and health. There are multiple methodological limitations that make robust interpretation challenging in many cases.

If you have enjoyed my work and want me to continue producing this sort of content, consider supporting me on Patreon. Every little bit helps! Thank you for your time! Enjoy!


Table of Contents


Anthropometrics

Cardiovascular

Chemistry

Endocrine

Inflammation

Kidney Function

Lipids/Lipoproteins

Liver Function

Thyroid Function

Energetics

Anthropometrics


Body Weight (kg)


Body Weight: Plant-based (vs Control)

Body Weight: Plant-based (vs Baseline)

Body Weight: Plant-based by Duration (vs Control)

Body Weight: Plant-based by Duration (vs Baseline)

Body Weight: Plant-based by Weight Loss (vs Control)

Body Weight: Plant-based by Weight Loss (vs Baseline)

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Body Fat Mass (kg)


Body Fat Mass: Plant-based (vs Control)

Body Fat Mass: Plant-based (vs Baseline)

Body Fat Mass: Plant-based by Duration (vs Control)

Body Fat Mass: Plant-based by Duration (vs Baseline)

Body Fat Mass: Plant-based by Weight Loss (vs Control)

Body Fat Mass: Plant-based by Weight Loss (vs Baseline)

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Fat Free Mass (kg)


Fat Free Mass: Plant-based (vs Control)

Fat Free Mass: Plant-based (vs Baseline)

Fat Free Mass: Plant-based by Duration (vs Control)

Fat Free Mass: Plant-based by Duration (vs Baseline)

Fat Free Mass: Plant-based by Weight Loss (vs Control)

Fat Free Mass: Plant-based by Weight Loss (vs Baseline)

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Body Mass Index


Body Mass Index: Plant-based (vs Control)

Body Mass Index: Plant-based (vs Baseline)

Body Mass Index: Plant-based by Duration (vs Control)

Body Mass Index: Plant-based by Duration (vs Baseline)

Body Mass Index: Plant-based by Weight Loss (vs Control)

Body Mass Index: Plant-based by Weight Loss (vs Baseline)

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Waist Hip Ratio


Waist Hip Ratio: Plant-based (vs Control)

Waist Hip Ratio: Plant-based (vs Baseline)

Waist Hip Ratio: Plant-based by Duration (vs Control)

Waist Hip Ratio: Plant-based by Duration (vs Baseline)

Waist Hip Ratio: Plant-based by Weight Loss (vs Control)

Waist Hip Ratio: Plant-based by Weight Loss (vs Baseline)

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Visceral Adipose Tissue (cm³)


Visceral Adipose Tissue: Plant-based (vs Control)

Visceral Adipose Tissue: Plant-based (vs Baseline)

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Intrahepatic Lipid (%)


Intrahepatic Lipid: Plant-based (vs Control)

Intrahepatic Lipid: Plant-based (vs Baseline)

Intrahepatic Lipid: Plant-based by Duration (vs Control)

Intrahepatic Lipid: Plant-based by Duration (vs Baseline)

Intrahepatic Lipid: Plant-based by Weight Loss (vs Control)

Intrahepatic Lipid: Plant-based by Weight Loss (vs Baseline)

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Intramyocellular Lipid (%)


Intramyocellular Lipid: Plant-based (vs Control)

Intramyocellular Lipid: Plant-based (vs Baseline)

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Cardiovascular


Systolic Blood Pressure (mmHg)


Systolic Blood Pressure: Plant-based (vs Control)

Systolic Blood Pressure: Plant-based (vs Baseline)

Systolic Blood Pressure: Plant-based by Duration (vs Control)

Systolic Blood Pressure: Plant-based by Duration (vs Baseline)

Systolic Blood Pressure: Plant-based by Weight Loss (vs Control)

Systolic Blood Pressure: Plant-based by Weight Loss (vs Baseline)

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Diastolic Blood Pressure (mmHg)


Diastolic Blood Pressure: Plant-based (vs Control)

Diastolic Blood Pressure: Plant-based (vs Baseline)

Diastolic Blood Pressure: Plant-based by Duration (vs Control)

Diastolic Blood Pressure: Plant-based by Duration (vs Baseline)

Diastolic Blood Pressure: Plant-based by Weight Loss (vs Control)

Diastolic Blood Pressure: Plant-based by Weight Loss (vs Baseline)

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Chemistry


Hemoglobin A1C (%)


Hemoglobin A1C: Plant-based (vs Control)

Hemoglobin A1C: Plant-based (vs Baseline)

Hemoglobin A1C: Plant-based by Duration (vs Control)

Hemoglobin A1C: Plant-based by Duration (vs Baseline)

Hemoglobin A1C: Plant-based by Weight Loss (vs Control)

Hemoglobin A1C: Plant-based by Weight Loss (vs Baseline)

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Blood Glucose (mg/dL)


Blood Glucose: Plant-based (vs Control)

Blood Glucose: Plant-based (vs Baseline)

Blood Glucose: Plant-based by Duration (vs Control)

Blood Glucose: Plant-based by Duration (vs Baseline)

Blood Glucose: Plant-based by Weight Loss (vs Control)

Blood Glucose: Plant-based by Weight Loss (vs Baseline)

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Uric Acid (mg/dL)


Uric Acid: Plant-based (vs Control)

Uric Acid: Plant-based (vs Baseline)

Uric Acid: Plant-based by Duration (vs Control)

Uric Acid: Plant-based by Duration (vs Baseline)

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White Blood Cell Count (×10³/mm³)


White Blood Cell Count: Plant-based (vs Control)

White Blood Cell Count: Plant-based (vs Baseline)

White Blood Cell Count: Plant-based by Duration (vs Control)

White Blood Cell Count: Plant-based by Duration (vs Baseline)

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Trimethylamine N-Oxide (μM)


Trimethylamine N-Oxide: Plant-based (vs Control)

Trimethylamine N-Oxide: Plant-based (vs Baseline)

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Malondialdehyde (μmol/L)


Malondialdehyde: Plant-based (vs Control)

Malondialdehyde: Plant-based (vs Baseline)

Malondialdehyde: Plant-based by Duration (vs Control)

Malondialdehyde: Plant-based by Duration (vs Baseline)

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Endocrine


Insulin (μU/mL)


Insulin: Plant-based (vs Control)

Insulin: Plant-based (vs Baseline)

Insulin: Plant-based by Duration (vs Control)

Insulin: Plant-based by Duration (vs Baseline)

Insulin: Plant-based by Weight Loss (vs Control)

Insulin: Plant-based by Weight Loss (vs Baseline)

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Insulin-Like Growth Factor 1 (ng/mL)


Insulin-Like Growth Factor 1: Plant-based (vs Control)

Insulin-Like Growth Factor 1: Plant-based (vs Baseline)

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Inflammation


High Sensitivity C-Reactive Protein (mg/L)


High Sensitivity C-Reactive Protein: Plant-based (vs Control)

High Sensitivity C-Reactive Protein: Plant-based (vs Baseline)

High Sensitivity C-Reactive Protein: Plant-based by Duration (vs Control)

High Sensitivity C-Reactive Protein: Plant-based by Duration (vs Baseline)

High Sensitivity C-Reactive Protein: Plant-based by Weight Loss (vs Control)

High Sensitivity C-Reactive Protein: Plant-based by Weight Loss (vs Baseline)

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Low Sensitivity C-Reactive Protein (mg/dL)


Low Sensitivity C-Reactive Protein: Plant-based (vs Control)

Low Sensitivity C-Reactive Protein: Plant-based (vs Baseline)

Low Sensitivity C-Reactive Protein: Plant-based by Duration (vs Control)

Low Sensitivity C-Reactive Protein: Plant-based by Duration (vs Baseline)

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Tumor Necrosis Factor (pg/mL)


Tumor Necrosis Factor: Plant-based (vs Control)

Tumor Necrosis Factor: Plant-based (vs Baseline)

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Intercellular Adhesion Molecule 1 (ng/mL)


Intercellular Adhesion Molecule 1: Plant-based (vs Control)

Intercellular Adhesion Molecule 1: Plant-based (vs Baseline)

Intercellular Adhesion Molecule 1: Plant-based by Duration (vs Control)