Is Intermittent Fasting Still Effective? Latest Research

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In the last few years, intermittent fasting (IF) has become very popular in the health industry. But as the trend grows, a lot of people are wondering if it will still work in 2025 or if it has lost its sparkle. New studies show that intermittent fasting is still good for many people, but it doesn't work for everyone. If you're thinking about it or already doing it, here's what the most recent research shows.
Disclaimer: This content is intended solely for informational and educational purposes and is not a substitute for professional medical advice, diagnosis, or treatment.Â
Table of Contents
- What Is Intermittent Fasting (IF)?
- What the Latest Research Says in 2025
- Benefits of Intermittent Fasting
- Potential Drawbacks and Who Should Avoid It
- Best Practices for Canadians Trying IF
What Is Intermittent Fasting (IF)?
Intermittent fasting is not a diet; it's a way of eating that includes periods of fasting and eating. Some of the most popular styles are:
- 16:8: You can eat for 8 hours and fast for 16 hours.
- 5:2: For two days, eat normally and cut back on calories (around 500–600).
- Fasting every other day means not eating anything for two days or only eating 25% of what you usually do.
- Early time-restricted feeding (eTRF) means eating between 8 a.m. and 4 p.m.
Intermittent fasting is different from regular diets since it focuses more on when you eat than what you consume.
What the Latest Research Says in 2025
Recent research shows that intermittent fasting is still useful, especially for metabolic health. But how well it works varies a lot on how often, when, and how different each person is.
A few important things to note:
- People still lose weight, but not always a lot. Many people who use IF lose weight without counting macros or calories.
- One of the most constant effects is that insulin sensitivity gets better, even in those who are not overweight.
- If you don't eat foods that are high in nutrients, the benefits may level off after a few months.
- It seems that early eating windows, such finishing dinner by 5 p.m., work better than late-night windows.
Researchers in Canada are also finding that lifestyle, cultural eating habits, and the amount of daylight in the winter can all affect IF performance, especially in the northern provinces.
Benefits of Intermittent Fasting
Intermittent fasting can help you reach a number of health goals if you do it right:
1. Keeping your weight in check
less meals usually imply less calories. Also, many people instinctively eat less when they fast.
2. Keeping blood sugar and insulin levels stable
Fasting for a short time makes insulin more sensitive and keeps blood sugar levels stable. This is good for people who are prediabetic or have metabolic syndrome.
3. Reduced Inflammation
Some studies have found that indicators like C-reactive protein (CRP) go down when people fast regularly.
4. Better digestion and a break for the gut
Fasting offers the digestive system a rest, which may help the gut and make you less bloated.
5. Health and Focus of the Brain
Many people say that fasting makes their minds clearer. Studies on animals also show that intermittent fasting may help protect the brain and slow down cognitive decline.
Potential Drawbacks and Who Should Avoid It
Some people can benefit from intermittent fasting, but not everyone can. Keep the following in mind:
1. Effects on hormones
If intermittent fasting is practiced too rigorously or without sufficient nourishment, it could disrupt some women's menstrual cycles or alter their levels of stress hormones.
2. The Danger of Not Eating Enough
If you skip meals, you might not eat enough by accident, especially if you don't eat much to begin with.
3. Making Eating Disorders WorseÂ
Eating IF can be bad for persons who have had eating disorders in the past or who are prone to going on strict diets.
4. Changes in mood and energy
When you initially start fasting, it can leave you weary, cranky, or not able to work out as much.
5. Not a good pick for everyone
Kids, pregnant women, those with diabetes or low blood pressure, or anybody with certain health problems should talk to a doctor before trying IF.
If you feel weak, dizzy, or excessively exhausted when you're fasting, that's not a good sign. Don't do what everyone else is doing; pay attention to your body.
Best Practices for Canadians Trying IF
Here are some tips to help you stay safe and get the most out of intermittent fasting:
- Take it easy. Try fasting for 12 hours at a time before moving on to 16:8 or more advanced routines.
- Drink a lot of water. You can drink water, herbal tea, and black coffee (in moderation) while you fast.
- To break your fast, eat whole foods. You need more than just fruit or toast. You also need protein, healthy fats, and fibre.
- Don't eat too much. Eating too much during meal windows can cancel out the benefits of IF and make your stomach hurt.
- Get enough sleep while you fast. If you don't get enough sleep, the metabolic and hormonal benefits of fasting may not work as well.
Quick Tip: In Canada, aim to eat throughout the day in the winter to keep your body's natural schedule in sync. This might help keep hunger hormones in check and make the findings better.
Final Thoughts: Is IF Still Worth It in 2025?
Many Canadians still think that intermittent fasting is a good and flexible way to eat, especially if they eat a lot of healthy foods and live a balanced life. But it's not magic. And not everyone needs it.
No matter if you fast or not, the secret to good health is still the same: eat well, move your body, get adequate sleep, and deal with stress.
Next, if you're interested in IF, start with a soft 12:12 pattern and see how it makes you feel. And if you're sick or on medicine, you should always talk to your doctor first.
References and Resources
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Intermittent Fasting: What is it, and how does it work? (2024, June 20). Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/wellness-and-prevention/intermittent-fasting-what-is-it-and-how-does-it-work
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Vasim, I., Majeed, C. N., & DeBoer, M. D. (2022). Intermittent fasting and metabolic health. Nutrients, 14(3), 631. https://doi.org/10.3390/nu14030631
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Time-restricted eating. . .or not. . .. (n.d.). Office for Science and Society. https://www.mcgill.ca/oss/article/health-and-nutrition/time-restricted-eatingor-not
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Clinic, C. (2025c, June 17). Intermittent fasting explained: Benefits and how to do it safely. Cleveland Clinic. https://health.clevelandclinic.org/intermittent-fasting-4-different-types-explained
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BSc, K. G. (2025, April 15). What is intermittent fasting and how does it affect the body? Healthline. https://www.healthline.com/nutrition/10-health-benefits-of-intermittent-fasting