Intermittent fasting, or IF, has gained a lot of popularity for its potential health benefits as a dietary pattern. Some IF users report more energy, weight loss, and improvements in metabolic health. (1) But intermittent fasting is not for everyone. There are some health considerations you may want to consider before you begin.
Some research suggests that people with specific health conditions, such as those that affect digestion or blood sugar or those at specific life stages, should use caution before starting intermittent fasting. (4) Let’s look at research-backed considerations to help you decide if intermittent fasting is right for you and your lifestyle.
Medical Conditions and Medications: Who Should Avoid Intermittent Fasting?
Before jumping on the intermittent fasting bandwagon, you should consider your personal medical history and current medications and, as always, talk to your doctor. In particular, people with diabetes, kidney stones, or gastroesophageal reflux disease should approach fasting with caution and receive individualized advice before beginning fasting. (4)(5)
Additionally, if you are taking medications for heart disease, blood sugar, high blood pressure, or medications that require food for proper absorption, intermittent fasting may impair your function or have negative side effects. (6) And anyone with a history of an eating disorder should avoid intermittent fasting, because any type of diet plan can trigger unhealthy patterns related to food restriction and binge eating. (7)
Health Conditions That Could Make Intermittent Fasting a Bad Idea
If you are taking medication for any health problem, including heart disease, diabetes, high blood pressure, or medications such as insulin and blood thinners, you may require regular food intake for proper absorption, intermittent fasting may not be suitable for you. you. (6)
Here are other health conditions that could make intermittent fasting the wrong approach for you:
- Diabetes: Fasting affects blood sugar levels, causing dangerous drops or unpredictable spikes. (4)
- kidney stones: Fasting may increase the risk of stone formation by affecting hydration status and dietary intake.(5)
- Underweight individuals: Fasting can cause greater weight loss, so it should be done under medical supervision and with regular health checks. (8)
- History of eating disorders: Fasting can lead to unhealthy eating patterns, making it unsafe for those suffering from past or present eating disorders. (7)
The impact of intermittent fasting on metabolism
One of the most discussed benefits of intermittent fasting is its impact on metabolism. Research suggests that fasting initiates fat burning through a process called ketosis. This is when the body burns fat for energy in the absence of carbohydrates. (1)
Additionally, intermittent fasting may improve insulin sensitivity, potentially reducing the risk of developing type 2 diabetes by lowering blood sugar levels and promoting better glucose control. (9)
However, some notable research notes that compared to other types of calorie-controlled diets, fasting was not associated with more significant weight loss than other types of calorie-restricted diet plans. (10)
This means that if you are not a good candidate for fasting, any type of diet that suits you can still work to help you achieve your weight loss goals.
Another metabolic benefit is autophagy, a cell repair and regeneration process that occurs with any type of calorie restriction. (11) This process has been linked to longevity and may protect against age-related diseases by removing damaged cells. (11)
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Hormonal effects: why fasting may be different for women
Women’s bodies are very sensitive to changes in calorie intake, which is why intermittent fasting can affect female hormones such as estrogen and progesterone. (12)
Studies show that prolonged fasting could disrupt women’s reproductive hormonal balance, which could lead to irregular menstrual cycles and unpleasant symptoms. (12) Importantly, women trying to conceive may want to avoid prolonged periods of fasting, as calorie restriction can negatively impact fertility. (12)
For pregnant or breastfeeding women, fasting can lead to nutrient deficiencies and insufficient calorie intake, which can affect the health of both mother and baby. (13) If you are a woman at this stage of life, consult your healthcare team before trying intermittent fasting.
Even outside of pregnancy, women with hormonal imbalances such as polycystic ovary syndrome (PCOS) should be careful about fasting. It can exacerbate symptoms. (13)
Ultimately, some research suggests that women may benefit from shorter fasting periods, such as 12 to 14 hours instead of a more restrictive 16-hour schedule. (14)
About the experts:
Carolina Thomason is a dietitian and diabetes educator who combines her love of nutrition with the power to make better health easy to understand. With 12 years in the industry, she has been published in over 40 publications, is a CPG consultant and advisor, speaker, broadcast spokesperson, and recipe developer.
Joanna Gregg He is the food data curator at MyFitnessPal. She earned her bachelor’s degree in Nutrition from Georgia State University and earned her master’s degree from the University of Nebraska.
Cortisol and stress: the science of fasting and the stress response
Intermittent fasting can also affect your levels of cortisol, a hormone responsible for controlling the stress response in the body. (15)
Prolonged fasting periods can increase cortisol production, especially if you are already stressed or sleep deprived. (15) Elevated cortisol levels appear to be associated with weight gain, particularly in the abdominal area, which may offset the weight loss benefits associated with fasting. (16)
Even more, high cortisol levels can cause you to stress about eating once your fasting window ends, creating a cycle of overeating followed by restrictive fasting. (17) This is a form of eating disorder and if you fall into this pattern, fasting may not be a good option for you. (17)
In general, if you are prone to stress or have difficulty controlling stress-related cravings, intermittent fasting may not be the best approach.
Blood sugar sensitivity: who should be careful?
If you have blood sugar problems, such as diabetes or hypoglycemia, you should be especially careful with intermittent fasting. (4) While fasting can improve insulin sensitivity, it can be risky for people with diabetes because prolonged fasting can lead to dangerously low blood sugar levels. (9)
Especially if you take insulin or other medications that affect blood glucose, fasting can increase your risk of hypoglycemia, which can cause serious symptoms such as dizziness, brain fog, confusion, or fainting. (18)
Even for those who don’t have diabetes, prolonged periods of fasting can cause drops in blood sugar, leading to irritability or a general feeling of fatigue. (19) If you have a blood sugar-related condition, consider shorter fasting periods or talk to a health professional to find the safest method for you.
Conclusion: Is Intermittent Fasting Right for You?
While intermittent fasting has become popular for its potential metabolic health benefits, it is not suitable for everyone. Before you begin, consider how fasting might affect your hormones, metabolism, stress levels, and blood sugar regulation.
With any new diet, consult a healthcare provider such as a dietician or your doctor. If fasting isn’t right for you, there are endless options for your nutrition plan to help you reach your goals.
And if you decide to try it, be sure to check out the Intermittent Fasting Tracker within the MyFitnessPal app.
Frequently asked questions
Does intermittent fasting cause or worsen gastroesophageal reflux disease (GERD)?
The research on intermittent fasting is mixed. There is some limited data showing that GERD symptoms may improve with fasting. (20)
What should be my first meal during intermittent fasting?
When breaking your fast during intermittent fasting, it is important to choose a balanced meal that provides essential nutrients. Whole food meals that provide lean protein, complex carbohydrates, and healthy fats are a good bet.
What can I drink in the morning during intermittent fasting?
If you want to avoid breaking your fast, opt for zero-calorie drinks like water, black coffee, or tea.
How MyFitnessPal Can Help
Whether you’ve already done intermittent fasting or are just curious about the potential health benefits of the eating pattern, MyFitnessPal’s Premium Intermittent Fasting Tracker feature can help! You can choose one of 3 fasting patterns depending on your lifestyle or goals:
12:12 – 12-hour fast, 12-hour eating window. This pattern is ideal for timing meals with your circadian rhythm.
14:10 – 14-hour fast and 10-hour feeding period. This pattern encourages regular meals and fewer snacks throughout the day.
16:8 – 16-hour fast, 8-hour eating window. This pattern usually involves skipping morning or afternoon meal times.
You’ll then be able to track your daily fasting periods in your journal, along with meals, water, and exercise. Ready to try it? Start a free trial of MyFitnessPal Premium today.
The post What to Know Before Starting Intermittent Fasting: 5 Scientific Considerations appeared first on the MyFitnessPal blog.
