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Metabolic health has become a popular topic among clinicians and the general public, and for good reason. Poor metabolic health — also called metabolic dysfunction — can increase the risk of diabetes, cancer, cardiovascular disease, dementia, and even Covid-19 complications.1

A 2019 publication reported only 12% of Americans were metabolically healthy — defined as having no criteria of metabolic syndrome free of medications.2 And a 2022 study reported only 6.8% of Americans had “optimal” levels of metabolic health markers.3

And the growing problem of metabolic dysfunction is not limited to the United States, but rather is a world-wide epidemic.4

But the news isn’t all bad. Scientific evidence and growing clinical experience show that you can improve your metabolic health. And you don’t need expensive drugs or procedures to do it.

You can improve your metabolic health with lifestyle interventions like nutrition and exercise. You just need to find the right advice for you to start making improvements today. If that’s what you’re looking for, you came to the right place!

metabolic-health-cardio
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What is metabolic health?

Traditionally, metabolic health is defined as a lack of metabolic syndrome, meaning having no more than two of the following criteria:5

  • Waist greater than or equal to 40 inches (102 cm) in men and 35 inches (88 cm) in women
  • Fasting glucose above 100 mg/dL (5.6 mmol/L) or HbA1c above 5.6% (38 mmol/mol)
  • Blood pressure above 120/80 mmHg
  • Triglycerides above 150 mg/dL (1.7 mmol/L)
  • High Density Lipoprotein (HDL) below 40mg/dL (1.04 mmol/L) for men and 50 mg/dL (1.3 mmol/L) for women

Different ethnicities may have different criteria for metabolic syndrome. For instance, South Asians have lower cut-offs for a healthy waist circumference of 35 inches (90 cm) for men and 31 inches (80 cm) for women.6 And Black Americans with insulin resistance frequently won’t have abnormal triglycerides and HDL, and therefore may not be identified as having metabolic syndrome.7

But health is not the same as an absence of disease. So while not having metabolic syndrome is a good starting point, we feel you can do better.

We define metabolic health as not requiring medications for and having healthy levels of the following:

  • body fat, especially minimal abdominal or visceral fat
  • blood sugar, without signs of insulin resistance
  • blood pressure
  • blood lipids, including HDL and triglycerides
  • muscle mass and body composition
  • resting metabolic rate

And we believe you should achieve these goals with a lifestyle that you enjoy, can maintain, and that leaves you feeling energetic and vibrant.


How to achieve metabolic health

Does achieving metabolic health seem difficult or out of reach? Do you look at the list above and think, how am I going to improve so many different aspects of my health? 

The good news is that many people can improve their metabolic health, and can improve multiple aspects of their health all at the same time. 

But the solution doesn’t come in a pill. The solution comes from how you live your life — how you eat, exercise, sleep, and manage your stress. 

Below are the best ways to improve your metabolic health, backed by science.

Nutrition

metabolic-health-nutritious-food

There’s more than one way to eat to improve your metabolic health. However, the best diets all share a few common threads:

  • They are minimally processed. 
  • They contain very little sugar. 
  • They allow you to reduce calories without the need to count calories. 
  • They satisfy your hunger. 
  • They provide adequate nutrition.

You may be able to improve your metabolic health by practically any eating pattern that helps you lose weight.8

The key to weight loss, however, is losing mostly fat mass without disproportionately losing muscle mass or reducing your resting metabolic rate.9

This can be a tricky balance.

The key is finding a way of eating that you enjoy and can maintain long-term that positively impacts your metabolic health.

But that doesn’t mean you need to lose weight to improve your metabolic health. Some lifestyle interventions can improve metabolic health well before any meaningful weight loss.10

Here are some dietary options from which you can choose.


Low carb for metabolic health

Eating a low-carb diet is an effective way to improve all aspects of metabolic health, including insulin sensitivity.11

One observational study even suggested improved survival for those with prediabetes who ate a lower carbohydrate diet, and a non-randomized trial reported glucose normalization in over 50% of participants with prediabetes.12

Although the data are not consistent, some studies suggest low-carb diets benefit metabolic health above and beyond their effect on weight loss. For instance, a 2006 study demonstrated lower insulin levels in people following a low-carb diet, despite equal weight loss compared to the control diet.13 And a 2019 randomized trial demonstrated following a low-carb diet improved metabolic syndrome better than a higher carb diet despite no difference in weight or fat mass loss.14

Yet another trial showed that a low-carb diet was better than a low-fat diet plus a popular prescription weight loss drug for lowering blood pressure, and just as good at improving HDL and triglycerides.15 Again, both groups lost the same amount of weight, but the diet with the lower carbohydrate levels achieved better metabolic results.

Improving metabolic health despite equal weight loss suggests that another mechanism is responsible for the health benefits. While the studies don’t define what the mechanism is, they suggest that it could have to do with lower insulin levels caused by lower carbohydrate intake. Further trials are needed to prove this. 

But even those trials that demonstrate greater weight loss with low-carb diets suggest it may be the type of weight loss that has beneficial effects. For instance, low-carb diets can help with fat loss better than other diets. Two randomized trials report significantly greater fat-mass loss with a low-carb diet compared to a low-fat diet.16

Summary

A low-carb diet can help improve all aspects of metabolic health. Studies demonstrate low-carb diets are as good as, or in many cases, even better than other diets (such as low-fat diets) for improving metabolic health. Low-carb diets may improve metabolic health even without significant weight loss.


High protein

Eating an adequate amount, or even a high amount of protein is another effective way of improving your metabolic health.

Higher protein diets consistently demonstrate improved blood sugar control, including helping to achieve diabetes remission. As with low-carb diets, some trials report greater metabolic benefits from high-protein diets even without significant weight loss compared to control diets.17

One small RCT even reported 100% prediabetes remission with a higher protein diet.18

In addition, the data are fairly consistent that most people would improve their lean muscle mass by increasing their protein intake.19

What’s a reasonable target amount of protein? As we describe in our protein guide, we define adequate protein as at least 1.2 grams per kilo of reference body weight per day.20 Increasing that to 1.6 grams per kilo may be even more beneficial for building muscle and improving metabolic health.21

Furthermore, the majority of the RCTs demonstrating improved metabolic health with a low-carb diet also increase protein consumption. That leads us to believe that the best approach for metabolic health may be a low-carb, high-protein diet.

Summary

Higher protein intake can help with many aspects of metabolic health including losing weight, building muscle mass, and improving insulin sensitivity. 


Intermittent fasting

Intermittent fasting is a popular dietary trend that limits eating to certain time windows. Studies suggest intermittent fasting can improve insulin sensitivity and metabolic health.22

Time-restricted eating is one type of intermittent fasting that involves eating meals in a set time-frame each day, such as between 11 am and 7 pm. A review of studies in healthy subjects showed that eating fewer meals during a shorter feeding window resulted in better glucose and insulin levels.23

Another type of intermittent fasting is alternate day fasting. Healthy males who fasted for 20 hours every other day for 15 days showed greater glucose uptake with the same insulin levels, in essence improving their insulin sensitivity.24

But not all studies agree. For instance, one RCT that did not control for how much or what the subjects ate didn’t demonstrate a benefit in lean mass for those fasting for 16 hours and restricting their meals to an eight-hour window.25 And another reported that alternate day fasting less effectively reduced fat mass than a matched degree of daily calorie restriction. There was also no evidence of fasting-specific effects on measured metabolic parameters.26

One potential conclusion to draw from these studies is that your diet quality and total calorie intake are still important, even when engaging in intermittent fasting.

Summary

While the data are sparse and inconclusive, various forms of intermittent fasting have the potential to be beneficial for metabolic health. We believe intermittent fasting can be a more powerful intervention when it results in relatively effortless calorie reduction, and when it is combined with another metabolically healthy eating pattern such as a low-carb, higher protein diet.


Other diets for metabolic health

Other dietary approaches can also help improve metabolic health. 

In a review comparing different clinical trials in adults with type 2 diabetes, people who followed a Mediterranean diet for 12 months lost an average of 13.5 pounds (6.2 kilos). This resulted in improvements in blood sugar, cholesterol, and blood pressure.27

Another review of Mediterranean diet trials in people with type 2 diabetes found that they are potentially more effective for lowering blood sugar levels than low-fat diets.28

A low-carb or keto Mediterranean diet may be even better than a classic Mediterranean diet for lowering blood sugar.29

Other studies suggest that Mediterranean diets can help people reduce body fat and their waist size, potentially contributing to metabolic improvements.30

And a systematic review of Mediterranean diet studies suggest it is effective for most components of metabolic health.31

Plant-based or vegan diets have also been shown to have a beneficial impact on metabolic health, although it’s not clear how much of the effect is due to weight loss vs other characteristics unique to plant-based diets. A systematic review of randomized trials found four out of eight trials demonstrated metabolic benefits with a plant-based diet, with some individual trials demonstrating greater weight loss and metabolic benefits over a “usual care” or the standard American diet.32 And other trials demonstrate beneficial effects on insulin sensitivity.33

Some evidence also supports the beneficial metabolic effects from a lower carb plant-based diet.34

Summary

Many different dietary approaches can improve the components of metabolic health. A low-carb, higher protein diet may be the most efficacious, but the key is finding an effective dietary pattern that you enjoy and can maintain long-term.


Exercise

Active senior man having strength exercise with barbell in a gym.

When you are first losing weight through your diet, you may not need to exercise much to maintain lean body mass. But as the weight continues to come off, then exercise becomes more important. And the good news is that exercise becomes more comfortable and more fun as you lose weight!35

Studies suggest that high-intensity interval training (HIIT), resistance training, and cardio training all improve glucose utilization, blood pressure, and insulin sensitivity.36

However, resistance training is superior when it comes to building muscle.37

For maximal metabolic health benefits, it appears a mix of resistance training, cardio, and HIIT may be the best approach.

No matter what your preferred form of movement or exercise, one thing is clear: inactivity can lead to insulin resistance and worsen metabolic health. And regular movement improves metabolic health.38 But if you stop moving regularly, your metabolic health may worsen. (Move it or lose it!)

You can learn more about the health impacts of exercise in our dedicated exercise guide and the section on exercise in our body composition guide.


Other lifestyle factors

Sleep

Studies show that short-term sleep deprivation raises glucose levels and blood pressure, and worsens insulin resistance and metabolic health.39

A chronic sleep disturbance, such as from obstructive sleep apnea, is also associated with worsening metabolic health.40

It’s unclear how much sleep is too little, just enough, or too much. Is there a difference in metabolic health in someone who gets six hours of sleep per night instead of eight? Is there a certain amount of lost sleep, or a frequency of bad nights that triggers metabolic dysfunction? We don’t know.

However, scientific studies support that there is an association between metabolic health and sleep. And treating sleep problems may improve metabolic health.41


Stress

Short term physiological and psychological stress, such as a sudden illness or sudden threat may induce temporary insulin resistance.42This type of insulin resistance reverses when the sudden stress is over. Such a response to short-term stress likely has no long-term negative consequences for metabolic health.

However, it appears that chronic stress and chronic activation of the body’s fight or flight response will potentially lead to persistent insulin resistance and worsening of metabolic health.43 Since this chronic stress is longer-term, without a sudden onset and quick resolution of the trigger, it may lead to longer-term negative consequences.

The good news is that you can reverse the negative effects. Two small controlled studies demonstrate that meditation alone helped reduce blood sugar and metabolic syndrome in patients with heart disease.44 Since mindfulness training, yoga, meditation, dancing, singing, and walking in nature can be effective ways to reduce stress, increase well-being and improve overall physical health, they may also help with metabolic health.


Medications and supplements

Old man taking pills

While some medications and supplements may help with individual components of metabolic health, few, if any, truly reverse the underlying problem and meaningfully impact all aspects of metabolic health. Only lifestyle interventions can do that.

Many doctors prescribe metformin for patients with prediabetes and/or insulin resistance. It works by decreasing glucose production by the liver and increasing the insulin sensitivity of cells.45

Pioglitazone is another medication that lowers blood sugar by enhancing the body’s sensitivity to insulin.46 This drug tends to not be as popular as metformin, however, in part due to the potential side effect of weight gain.

Blood pressure medications can improve blood pressure, but many may worsen other components of metabolic health. For instance, beta-blockers can lead to weight gain, potentially worsening other aspects of metabolic health.

Weight loss drugs, such as liraglutide, a GLP-1 agonist medication, can help people lose weight; this may be enough to improve most aspects of metabolic health. However, these drugs come with a cost and potential side effects, and they only benefit you while you are taking them. Once you stop, studies show the weight tends to come back and the metabolic improvements disappear.47

Niacin can raise HDL and lower triglycerides, but again, it doesn’t impact the underlying cause of metabolic disease. In fact, it can worsen insulin resistance and raise blood sugar, thereby potentially worsening overall metabolic health.48

Berberine has a similar effect to metformin and may improve insulin sensitivity and triglycerides.49 However, it has little effect on other aspects of metabolic health.

Green tea may have modest metabolic benefits helping with weight loss and reducing both waist size and blood pressure.50

Summary

Multiple medications may improve individual components of metabolic dysfunction, but none address all components of metabolic health or effectively reverse the underlying causes of poor health.


How to measure metabolic health

Bodyweight is an incomplete metric to follow for metabolic health. As we mentioned previously, some data demonstrate that you can significantly improve your metabolic health without meaningful weight loss. And if you are losing weight, the type of weight loss may be more important than the absolute amount.

Tracking your body composition — your fat mass, muscle mass, and overall lean mass — gives much better insight into your metabolic health. You can learn more about testing your body composition in our dedicated guide. 

Measuring your waist circumference is the easiest metric for metabolic health. A DEXA scan is likely the most accurate and informative, and a bioimpedance scale bridges the gap between accuracy and availability/affordability.

But metabolic health also involves blood pressure, blood sugar, lipids, and metabolic rate.  

Home blood pressure cuffs are widely available and fairly easy to use. You can learn more in our guide on blood pressure.

Your doctor may order blood tests for your fasting blood sugar or a hemoglobin A1c . But a continuous glucose monitor, a small device that gives you a running reading of your blood glucose level, may be an even more helpful way to monitor your blood sugar. You can learn more about CGMs in our detailed guide

Another helpful metric is your resting metabolic rate (RMR). Your RMR is roughly the amount of energy, or calories, you burn naturally, without exercise, during the day. You can hear a detailed discussion about RMR and how knowing your results may impact your health in our podcast interview with Kirsty Woods, Ph.D


More information on metabolic health 

Are you looking for more information about the individual components of metabolic health? You’re in luck. We have guides on just about every aspect of metabolic health. Here are some of the best places to look for more information.


Get started today to improve your metabolic health

If you want to get started improving your metabolic health today, you may want to explore our low-carb or keto diet guides. You can also sign up for our free 2-week keto low-carb challenge!
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How to achieve metabolic health - the evidence

This guide is written by Dr. Bret Scher, MD and was last updated on August 6, 2022. It was medically reviewed by Dr. Michael Tamber, MD on August 5, 2022.

The guide contains scientific references. You can find these in the notes throughout the text, and click the links to read the peer-reviewed scientific papers. When appropriate we include a grading of the strength of the evidence, with a link to our policy on this. Our evidence-based guides are updated at least once per year to reflect and reference the latest science on the topic.

All our evidence-based health guides are written or reviewed by medical doctors who are experts on the topic. To stay unbiased we show no ads, sell no physical products, and take no money from the industry. We're fully funded by the people, via an optional membership. Most information at Diet Doctor is free forever.

Read more about our policies and work with evidence-based guides, nutritional controversies, our editorial team, and our medical review board.

Should you find any inaccuracy in this guide, please email andreas@dietdoctor.com.

  1. Metabolism Open 2020: The incidence of COVID-19 in patients with metabolic syndrome and non-alcoholic steatohepatitis: A population-based study [non-controlled study; weak evidence]

    JAMA 2002: The metabolic syndrome and total and cardiovascular disease mortality in middle-aged men
    [non-controlled study; weak evidence]

    Diabetes Care 2012: Metabolic syndrome and risk of cancer: A systematic review and meta-analysis [meta-analysis of observational studies; weak evidence]

  2. The authors defined metabolic health as not taking any related medications and having none of the following criteria:

    • Waist greater than or equal to 40 inches (102 cm) in men and 35 inches (88 cm) in women
    • Fasting glucose above 100 mg/dL (5.6 mmol/L) or HbA1c above 5.6% (38 mmom/mol)
    • Blood pressure above 120/80 mmHg
    • Triglycerides above 150 mg/dL (1.7 mmol/L)
    • High Density Lipoprotein (HDL) below 40 mg/dL (1.04 mmol/L) for men and 50 mg/dL (1.3 mmol/L) for women

    However, the definition of metabolic syndrome is the presence of any three of the above criteria.

    Metabolic Syndrome and Related Disorders 2019: Prevalence of optimal metabolic health in American adults: National health and nutrition examination survey 2009-2016
    [non-controlled study; weak evidence]

  3. Journal of the American College of Cardiology 2022: Trends and Disparities in Cardiometabolic Health Among U.S. Adults, 1999-2018[non-controlled study; weak evidence]

  4. Current Hypertension Reports 2018: The global epidemic of the metabolic syndrome [overview article; ungraded]

  5. Circulation 2004: Definition of metabolic syndrome: Report of the national heart, lung, and blood institute/American heart association conference on scientific issues related to definition [overview article; ungraded]

  6. Nutrients 2019: Ethnicity and metabolic syndrome: implications for assessment, management and prevention [overview article; ungraded]

  7. Metabolic Syndrome and Related Disorders 2012: The triglyceride paradox in people of African descent [overview article; ungraded]

    Atherosclerosis 2008: Ethnic differences in the ability of triglyceride levels to identify insulin resistance
    [observational study; weak evidence]

  8. Cell Metabolism 2016: Effects of moderate and subsequent progressive weight loss on metabolic function and adipose tissue biology in humans with obesity [randomized trial; moderate evidence]

    NEJM 2002: Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin
    [randomized trial; moderate evidence]

  9. Medicine, Science, Sports and Exercise 2017: Effects of weight loss on lean mass, strength, bone, and aerobic capacity [randomized trial; moderate evidence]

    An evaluation of participants from the “Biggest Loser” television show found that, six years after the contestants underwent severe caloric restriction and exercise found their metabolic rates remained drastically decreased. The decrease was more than expected given the magnitude of initial amount of weight loss, and the metabolic rate remained depressed despite eventual weight regain.

    Obesity 2016: Persistent metabolic adaptation 6 years after “The Biggest Loser” competition
    [non-controlled study; weak evidence]

  10. This RCT reported those following a diet with 27% protein compared to 16% had better body composition with preservation of lean mass and a better glycemic response, despite no difference in weight loss.

    Nutrients 2018: Effects of adherence to a higher protein diet on weight loss, markers of health, and functional capacity in older women participating in a resistance-based exercise program
    [randomized trial; moderate evidence]

    And the following case series reports on three patients who had dramatic improvements in blood sugar, HDL, and triglycerides despite little weight loss.

    Frontiers in Nutrition 2021: Treating diabetes utilizing a low carbohydrate ketogenic diet and intermittent fasting without significant weight loss: A case report [case series, very weak evidence]

  11. Journal of the American College of Nutrition 2013: Improvements in glucose metabolism and insulin sensitivity with a low-carbohydrate diet in obese patients with type 2 diabetes [uncontrolled study; weak evidence]

    JCI Insight 2019: Dietary carbohydrate restriction improves metabolic syndrome independent of weight loss [randomized trial; moderate evidence]

    Obesity 2015: Weight loss on low-fat vs. low-carb diets by insulin resistance status among overweight adults & adults with obesity: A randomized pilot trial [moderate evidence]

    Lipids 2009: Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet [randomized trial; moderate evidence]

    Three meta-analyses of randomized trials demonstrate the triglyceride lowering effects of low-carb diets:

    PLoS One 2020: The effects of low-carbohydrate diets on cardiovascular risk factors: A meta-analysis [systematic review of randomized trials; strong evidence]

    Nutrition Reviews 2019: Effects of carbohydrate-restricted diets on low-density lipoprotein cholesterol levels in overweight and obese adults: A systematic review and meta-analysis [systematic review of randomized trials; strong evidence]

    European Journal of Clinical Nutrition 2018: The interpretation and effect of a low-carbohydrate diet in the management of type 2 diabetes: A systematic review and meta-analysis of randomised controlled trials [systematic review of randomized trials; strong evidence]

  12. Clinical Nutrition 2020:
    Associations of low-carbohydrate and low-fat intakes with all-cause mortality in subjects with prediabetes with and without insulin resistance
    [observational study, weak evidence]

    Nutrients 2021: Type 2 diabetes prevention focused on normalization of glycemia: A two-year pilot study [nonrandomized study, weak evidence]

  13. Nutrition & Metabolism 2006: Comparison of isocaloric very low carbohydrate/high saturated fat and high carbohydrate/low saturated fat diets on body composition and cardiovascular risk [randomized trial; moderate evidence]

  14. JCI Insight 2019: Dietary carbohydrate restriction improves metabolic syndrome independent of weight loss [randomized trial; moderate evidence]

  15. While glucose, insulin, and HbA1c levels improved only in the low-carb group, there was no statistical difference in these values between the low-carb and low-fat groups.

    Journal of the American Medical Association 2010: A randomized trial of a low-carbohydrate diet vs orlistat plus a low-fat diet for weight loss [moderate evidence]

  16. In one randomized trial, low-carb dieters lost 22.8% of their abdominal fat, compared to only 1% for the low-fat dieters.

    Nutrition and Metabolism (London) 2020: Effects of weight loss during a very low carbohydrate diet on specific adipose tissue depots and insulin sensitivity in older adults with obesity: A randomized clinical trial [randomized trial; moderate evidence]

    And another study reports an 11% body fat reduction for low-carb eaters compared to a 1% reduction for low-fat dieters.

    Journal of Nutrition 2015: A lower-carbohydrate, higher-fat diet reduces abdominal and intermuscular fat and increases insulin sensitivity in adults at risk of type 2 diabetes [randomized trial; moderate evidence]

  17. This RCT reported those following a diet with 27% protein compared to 16% had better body composition with preservation of lean mass and a better glycemic response, despite no difference in weight loss.

    Nutrients 2018: Effects of adherence to a higher protein diet on weight loss, markers of health, and functional capacity in older women participating in a resistance-based exercise program
    [randomized trial; moderate evidence]

    This randomized crossover study reported subjects with type 2 diabetes had a greater reduction in HbA1c, total daily glucose, fatty liver, and fatty pancreas with a diet that includes 30% of energy from protein and 30% from carbs, compared to a diet that includes 17% of energy from protein and 50% from carbohydrate.

    Diabetologia 2019: A carbohydrate-reduced high-protein diet improves HbA1c and liver fat content in weight stable participants with type 2 diabetes: A randomised controlled trial [randomized trial; moderate evidence]

  18. Nutrition, Metabolism, and Cardiovascular Diseases 2020: High protein diet leads to prediabetes remission and positive changes in incretins and cardiovascular risk factors [randomized trial; moderate evidence]

  19. A meta-analysis of RCTs demonstrates that eating more protein leads to better muscle gains.

    Journal of Nutrition 2020: The role of protein intake and its timing on body composition and muscle function in healthy adults: A systematic review and meta-analysis of randomized controlled trials [strong evidence]

    Observational studies show those who eat more protein have greater muscle mass.

    American Journal of Clinical Nutrition 2016: Relation between mealtime distribution of protein intake and lean mass loss in free-living older adults of the NuAge study [nutritional epidemiology study with HR<2, very weak evidence]

    American Journal of Clinical Nutrition 2008: Dietary protein intake is associated with lean mass change in older, community-dwelling adults: the Health, Aging, and Body Composition (Health ABC) Study [nutritional epidemiology study with HR<2, very weak evidence]

    British Journal of Nutrition 2016: Dietary protein intake is associated with better physical function and muscle strength among elderly women [nutritional epidemiology study with HR<2, very weak evidence]

  20. “Reference body weight” is a rough approximation of your lean body mass – the part that needs protein. You can look up your reference body weight here or use the simple chart below to estimate your protein needs.

  21. British Journal of Sports Medicine 2018: A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults [strong evidence]

  22. American Journal of Clinical Nutrition 2009: Short-term modified alternate-day fasting: A novel dietary strategy for weight loss and cardioprotection in obese adults [non-controlled study; weak evidence]

    American Journal of Clinical Nutrition 2007: Alternate-day fasting and chronic disease prevention: a review of human and animal trials [overview article; ungraded]

  23. Nutrition Review 2014: Time-restricted feeding and risk of metabolic disease: A review of human and animal studies [overview article; ungraded]

  24. Journal of Applied Physiology 2005: Effect of intermittent fasting and refeeding on insulin action in healthy men [uncontrolled intervention trial; weak evidence]

  25. JAMA Internal Medicine 2020: Effects of time-restricted eating on weight loss and other metabolic parameters in women and men with overweight and obesity: The TREAT randomized clinical trial [randomized trial; moderate evidence]

  26. Science and Translational Medicine 2021:
    A randomized controlled trial to isolate the effects of fasting and energy restriction on weight loss and metabolic health in lean adults
    [randomized trial; moderate evidence]

  27. Journal of the Academy of Nutrition and Dietetics 2015: Lifestyle weight-loss intervention outcomes in overweight and obese adults with type 2 diabetes: A systematic review and meta-analysis of randomized clinical trials [strong evidence]

  28. BMJ Open 2015: A journey into a Mediterranean diet and type 2 diabetes: A systematic review with meta-analyses [strong evidence]

  29. In a 12-month trial of overweight adults with type 2 diabetes, those who ate a low-carb Mediterranean diet reduced their HbA1c by 2%, which was significantly better than the 1.6% reduction with the ADA diet:

    Diabetes, Obesity & Metabolism 2010: A low carbohydrate Mediterranean diet improves cardiovascular risk factors and diabetes control among overweight patients with type 2 diabetes mellitus: A 1-year prospective randomized intervention study [randomized trial; moderate evidence]

    In a 2011 trial, 22 people with metabolic syndrome who followed a Mediterranean ketogenic diet for 12 weeks reduced their fasting blood sugar by 27 mg/dL, on average:

    Journal of Medicinal Food 2011: A pilot study of the Spanish Ketogenic Mediterranean Diet: an effective therapy for the metabolic syndrome [non-randomized trial; weak evidence]

  30. In one trial, people who followed a Mediterranean diet lost up to 7.5 pounds (3.4 kilos) and 2.74% of their body fat in four weeks:

    Journal of Translational Medicine 2018: Influence of FTO rs9939609 and Mediterranean diet on body composition and weight loss: A randomized clinical trial [randomized trial; moderate evidence]

    A 2018 review looked at several trials that tested a Mediterranean diet for weight loss. In 13 of 18 trials, people who were assigned to follow a Mediterranean diet lost an average of four inches (10 cm) from around their waist.

    However, seven of the trials restricted calories, and only three of those trials reported significantly greater weight loss in the Mediterranean diet groups compared to the calorie-restricted control groups:

    Critical Reviews in Food Science and Nutrition 2018: Central obesity and the Mediterranean diet: A systematic review of intervention trials [strong evidence]

  31. Nutrients 2020: The effect of the mediterranean diet on metabolic health: A systematic review and meta-analysis of controlled trials in adults
    [systematic review of randomized trials; strong evidence]

  32. Diabetes, Metabolic Syndrome, and Obesity 2020: Effects of plant-based diets on outcomes related to glucose metabolism: A systematic review
    [systematic review of randomized trials; strong evidence]

    Nutrition and Diabetes 2018: A plant-based diet in overweight individuals in a 16-week randomized clinical trial: Metabolic benefits of plant protein
    [randomized trial; moderate evidence]

  33. JAMA Network Open 2020: Effect of a low-fat vegan diet on body weight, insulin sensitivity, postprandial metabolism, and intramyocellular and hepatocellular lipid levels in overweight adults: A randomized clinical trial
    [randomized trial; moderate evidence]

  34. BMJ Open 2014: Effect of a 6-month vegan low-carbohydrate (‘Eco-Atkins’) diet on cardiovascular risk factors and body weight in hyperlipidaemic adults: A randomised controlled trial [moderate evidence]

  35. This is based on the consistent clinical experience of practitioners familiar with low-carb nutrition. [weak evidence]

  36. British Medical Journal Open Sport Exercise Medicine 2016: Update on the effects of physical activity on insulin sensitivity in humans [overview article; ungraded]

  37. Journal of Applied Physiology 1985:
    Effects of aerobic and/or resistance training on body mass and fat mass in overweight or obese adults
    [randomized trial; moderate evidence]

    Combining resistance training and high-intensity cardio may help you gain muscle mass and lose fat mass. “Interventions that combine high-intensity aerobic and high-load resistance training exert beneficial effects that are superior to any other exercise modality at decreasing abdominal adiposity, improving lean body mass, and increasing cardiorespiratory fitness”.

    Obesity Reviews 2021: What exercise prescription is optimal to improve body composition and cardiorespiratory fitness in adults living with obesity? A network meta-analysis [review of observtional and reandomized studies; weak evidence]

  38. Journal of Obesity and Weight Loss 2015: Exercise training and insulin resistance: A current review [overview article; ungraded]

  39. Lancet 1999: Impact of sleep debt on metabolic and endocrine function [non-randomized study; weak evidence]

    Healthcare (Basel) 2019: The interlinked rising epidemic of insufficient sleep and diabetes mellitus [overview article; ungraded]

  40. Clinical Endocrinology 2003: Obstructive sleep apnoea syndrome impairs insulin sensitivity independently of anthropometric variables [cohort study; weak evidence]

  41. European Respiratory Journal 2010: A randomised controlled trial of nasal continuous positive airway pressure on insulin sensitivity in obstructive sleep apnoea [moderate evidence]

  42. Journal of Endocrinology 2013: Acute psychological stress results in the rapid development of insulin resistance [mouse study; very weak evidence]

    In theory, this could have been an evolutionary advantage at some point in human existence and has been termed “adaptive insulin resistance”. The following paper hypothesizes that insulin resistance played a role in our evolution and may have been a natural adaptation to illness, injury, or temporary starvation.

    Metabolism 2013: Insulin resistance: An adaptive mechanism becomes maladaptive in the current environment — An evolutionary perspective [overview article; ungraded]

  43. Psychoneuroendocrinology 2005: Role of stress in the pathogenesis of the metabolic syndrome [overview article; ungraded]

    Journal of Epidemiology 2016: Investigation of the relationship between chronic stress and insulin resistance in a Chinese population [prospective cohort study; weak evidence]

  44. While the change in insulin levels among meditators from the beginning to the end of the studies was not statistically significant, meditators had significantly lower insulin levels than control subjects by the end of each study.

    We can postulate that meditation may have contributed to maintenance of health in the intervention groups, while the non-meditators showed a slight decline in metabolic health.

    International Journal of Yoga 2018: Effect of 6 months of meditation on blood sugar, glycosylated hemoglobin, and insulin levels in patients of coronary artery disease [randomized trial; moderate evidence]

    Archives of Internal Medicine 2006: Effects of a randomized controlled trial of transcendental meditation on components of the metabolic syndrome in subjects with coronary heart disease [moderate evidence]

  45. Diabetes & Metabolism 2003: Reducing insulin resistance with metformin: The evidence today [review article; ungraded]

  46. Current Diabetes Report 2019: Thiazolidinediones: The forgotten diabetes medications [overview article; ungraded]

  47. JAMA 2021: Effect of continued weekly subcutaneous semaglutide vs placebo on weight loss maintenance in adults with overweight or obesity: The STEP 4 randomized clinical trial [randomized trial; moderate evidence]

  48. American Journal of Cardiology 2008: Mechanism of action of niacin [overview article; ungraded]

    American Journal of Medicine 2017: Role of niacin in current clinical practice: A systematic review
    [overview article; ungraded]

  49. International Journal of Endocrinology 2015: Application of berberine on treating type 2 diabetes mellitus
    [overview article; ungraded]

  50. This study showed significant improvement in the intervention group, but there was no statistically significant difference in any measured parameters between the tea-drinkers and the non-tea-drinkers

    Journal of Research and Medical Science 2013: The effects of green tea consumption on metabolic and anthropometric indices in patients with type 2 diabetes [randomized trial; moderate evidence]