Intermittent Fasting Appetite Control Summary
- The study included 17 randomized controlled trials that measured appetite during intermittent fasting appetite control interventions compared to continuous energy restriction on appetite and other outcomes.
- The meta-analysis showed no clear evidence that intermittent fasting interventions affect weight loss differently from continuous energy restriction.
- The study’s main findings were that there was no clear evidence that intermittent fasting interventions had a different effect on hunger, fullness, desire to eat, or prospective food consumption compared to continuous energy restriction interventions.
Intermittent fasting (IF) and calorie restriction are two popular methods for appetite control, but which one is truly effective? IF has gained popularity recently, with many fitness enthusiasts and low-carb dieters swearing for its benefits for appetite control. However, is it truly superior to traditional calorie restriction for suppressing appetite? This article aims to discuss a recent study on IF and appetite control and debunk the myth that IF is better for appetite control than calorie restriction.
Intermittent Fasting vs. Time Restricted Eating: What is the Difference?
IF and time-restricted eating are the newest rages in dieting. In contrast to traditional, continuous dietary restriction, which requires counting calories and strict adherence to a diet, with no opportunity for flexibility. For this reason, individuals who follow an IF regime may find it easier to lose weight. (Liu et al., 2020)
IF and Time Restricted Eating have been suggested to help you lose weight, increase youthful hormones, suppress appetite, extend your life, and make your skin healthier. Time-restricted eating (TRE) and IF are dietary strategies that involve periods of eating and fasting, but they differ in their approach and flexibility.
Time-Restricted Eating (TRE): This method involves setting a specific eating window each day, typically ranging from 6 to 12 hours, and fasting for the remainder of the day. For example, someone following a 16:8 TRE plan would eat all their meals within an 8-hour window (say, from 12 PM to 8 PM) and fast for the remaining 16 hours (from 8 PM to 12 PM the next day).
TRE focuses more on when you eat rather than what you eat, although maintaining a balanced diet is still important for overall health. Time-restricted feeding curtails food intake anywhere from 4 to 18 hours and is a proposed long-term weight loss strategy. (Di Francesco et al., 2018; Panda, 2016)
How Does Intermittent Fasting Work?
Intermittent Fasting (IF): This broader term encompasses several different fasting methods, including TRE. Other forms of IF include the 5:2 diet (eating normally for five days of the week and restricting calories to about 500-600 on two non-consecutive days) and alternate-day fasting (alternating between days of normal eating and days of fasting or severe calorie restriction).
The key difference between TRE and other forms of IF is the regularity and predictability of the eating and fasting periods. With TRE, the eating and fasting windows are generally the same each day, whereas other forms of IF may involve varying periods of eating and fasting from day to day or week to week.
Intermittent Fasting vs. Calorie Restriction for Weight Loss
Recent studies have taken the air out of the time-restricted eating hot air balloon when they found no difference in weight or fat loss compared to an identical calorie-matched diet. (Liu et al., 2022; Lowe et al., 2020) However, time-restricted eating did have beneficial effects beyond weight loss, such as improved glucose control, reduced blood pressure, and improved lipid profiles.
How Hormones Influence Appetite Control and Food Intake
Research indicates that hormones, such as ghrelin and leptin, play a crucial role in appetite regulation. Ghrelin stimulates hunger, while leptin signals fullness. Both IF and calorie restriction, which are different approaches to appetite control, can affect hormone levels.
IF has been found to lead to changes in hormone levels that may help decrease appetite. On the other hand, the effects of calorie restriction on hormone levels depend on factors like age and gender. By understanding the influence of hormones on appetite control, individuals can evaluate the effectiveness of various dietary strategies for weight loss and improving overall metabolic health.
The Science: Appetite Control in Intermittent Fasting and Calorie Restriction
Based on previous reviews, it has been suggested that IF and TRE reduce appetite. (Hoddy et al., 2020; Liu et al., 2020; Seimon et al., 2015; Steger et al., 2023) This means that individuals who undergo IF may experience a decrease in their desire to eat. Seimon et al. found that IF can potentially weaken the body’s natural response to increase the urge to eat during long-term continuous energy restriction.
They observed that in six out of ten clinical trials, appetite either decreased or remained unchanged following IF interventions. Additionally, a more recent review by Liu et al. reported that participants who engaged in IF experienced a decrease in hunger and an increase in feelings of fullness compared to their appetite levels before the intervention.
IF regulates hunger hormones by restricting eating to specific time windows. On the other hand, calorie restriction reduces overall daily calorie intake, gradually decreasing appetite. Combining IF and calorie restriction may offer a viable appetite control and weight management solution.
A recent study examined all the IF studies to examine its effect on appetite control. A 2022 review of the research reported inconclusive research that alternate-day fasting, a type of IF, resulted in greater appetite suppression. (Kucuk & Berg, 2022)
The Myth: Intermittent Fasting Appetite Control is Better than Continuous Dietary Restriction
Many proponents of IF argue that it’s superior for appetite control. They claim that fasting periods help regulate hunger hormones, reducing appetite and cravings. However, scientific evidence suggests otherwise.
A recent study titled “The Effect of Intermittent Fasting on Appetite: A Systematic Review and Meta-Analysis” by Rebecca L. Elsworth, published in the journal Nutrients is causing some controversy.
The study is a systematic review and meta-analysis that investigates the effects of IF on appetite, comparing it to continuous energy restriction interventions. The authors analyzed 17 randomized controlled trials (RCTs) involving various IF regimes. The total number of participants across these trials was 1,111.
The key findings from the study are as follows: There was no clear evidence that IF affected hunger, fullness, desire to eat, or prospective food consumption differently than continuous energy restriction interventions. The results suggest that IF does not mitigate an increase in our drive to eat, often associated with continuous energy restriction.
The study found no significant differences between IF and continuous energy restriction interventions regarding energy intake, eating behavior, physical activity, adherence to interventions, or dropout. (Elsworth et al., 2023)
The Verdict: Intermittent Fasting Appetite Control vs. Calorie Restriction
While intermittent fasting can be useful for weight loss and health improvement, it’s not necessarily superior to calorie restriction for appetite control. Both methods can lead to similar appetite control and weight loss outcomes, provided they are followed correctly.
Practical Tips for Intermittent Fasting and Calorie Restriction
If you’re considering trying intermittent fasting or calorie restriction, here are some practical tips:
- Start Slowly: Gradually increase the duration of your fasting periods or decrease your daily calorie intake to give your body time to adjust.
- Stay Hydrated: Drink plenty of water during fasting and eating.
- Eat Balanced Meals: Ensure your meals are balanced with adequate protein, healthy fats, and fiber-rich carbohydrates.
- Listen to Your Body: Listen to your body’s hunger and fullness cues. If you’re feeling excessively hungry or deprived, it may be a sign that you need to adjust your diet plan.
The notion that intermittent fasting is superior to calorie restriction for appetite control is not supported by scientific evidence. Depending on individual preferences and lifestyle, both methods can effectively control weight loss and appetite. Choosing a method that is sustainable in the long term is essential, as consistency is key for successful weight loss and maintenance.
Before starting any new diet regimen, please consult a healthcare professional or a registered dietitian to ensure it suits your health needs.
Elsworth, R. L., Monge, A., Perry, R., Hinton, E. C., Flynn, A. N., Whitmarsh, A., Hamilton-Shield, J. P., Lawrence, N. S., & Brunstrom, J. M. (2023). The Effect of Intermittent Fasting on Appetite: A Systematic Review and Meta-Analysis. Nutrients, 15(11). https://doi.org/10.3390/nu15112604
Hoddy, K. K., Marlatt, K. L., Çetinkaya, H., & Ravussin, E. (2020). Intermittent Fasting and Metabolic Health: From Religious Fast to Time-Restricted Feeding. Obesity, 28(S1), S29-S37. https://doi.org/https://doi.org/10.1002/oby.22829
Kucuk, B., & Berg, R. C. (2022). Alternate Day Fasting on Subjective Feelings of Appetite and Body Weight for Adults With Overweight or Obesity: A Systematic Review. Journal of Nutritional Science. https://doi.org/10.1017/jns.2022.90
Liu, D., Huang, Y., Huang, C., Yang, S., Wei, X., Zhang, P., Guo, D., Lin, J., Xu, B., Li, C., He, H., He, J., Liu, S., Shi, L., Xue, Y., & Zhang, H. (2022). Calorie Restriction with or without Time-Restricted Eating in Weight Loss. New England Journal of Medicine, 386(16), 1495-1504. https://doi.org/10.1056/NEJMoa2114833
Liu, K., Liu, B., & Heilbronn, L. K. (2020). Intermittent fasting: What questions should we be asking? Physiology & Behavior, 218, 112827. https://doi.org/https://doi.org/10.1016/j.physbeh.2020.112827
Lowe, D. A., Wu, N., Rohdin-Bibby, L., Moore, A. H., Kelly, N., Liu, Y. E., Philip, E., Vittinghoff, E., Heymsfield, S. B., Olgin, J. E., Shepherd, J. A., & Weiss, E. J. (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. JAMA Internal Medicine, 180(11), 1491-1499. https://doi.org/10.1001/jamainternmed.2020.4153
Seimon, R. V., Roekenes, J. A., Zibellini, J., Zhu, B., Gibson, A. A., Hills, A. P., Wood, R. E., King, N. A., Byrne, N. M., & Sainsbury, A. (2015). Do intermittent diets provide physiological benefits over continuous diets for weight loss? A systematic review of clinical trials. Molecular and Cellular Endocrinology, 418, 153-172. https://doi.org/https://doi.org/10.1016/j.mce.2015.09.014
Steger, F. L., Jamshed, H., Martin, C. K., Richman, J. S., Bryan, D. R., Hanick, C. J., Salvy, S.-J., Warriner, A. H., & Peterson, C. M. (2023). Impact of early time-restricted eating on diet quality, meal frequency, appetite, and eating behaviors: A randomized trial. Obesity, 31(S1), 127-138. https://doi.org/https://doi.org/10.1002/oby.23642
Does intermittent fasting work?
IF has gained significant attention in recent years as a popular approach for weight loss and improving metabolic health. Several studies have explored the effects of intermittent fasting on various aspects, such as appetite control, weight loss, and overall well-being.
IF is a type of diet that has been gaining popularity, especially on social media, for its potential health benefits and as a lifestyle change for weight management. It involves cycling between periods of eating and fasting, with the number of hours for each varying based on the specific type of IF you’re following. This diet has been linked to various health benefits, from improved metabolism and heart health to longer life and reduced inflammation.
Calorie Control VS IF
One of the key aspects of IF is its impact on metabolism. By restricting the hours you eat, your body is forced to shift its energy source from the food you’ve just eaten to the stored fats, which can lead to weight loss. This process also affects insulin, the hormone that regulates blood sugar levels. IF can improve insulin resistance, which means your body can use insulin more effectively to control blood sugar levels.
However, like any diet, IF comes with potential side effects. Some people may experience headaches, nausea, or hunger pangs, especially in the initial stages, as the body adjusts to the new eating schedule. It’s also important to maintain a healthy diet during the eating periods. This means consuming a balanced diet rich in whole grains, lean protein, legumes, veggies, and healthy fats like avocado and olive oil. Snacks like yogurt can also be included.
For those with health conditions such as high blood pressure or heart disease, it’s crucial to consult with a healthcare provider before starting IF. Certain prescription medications, including prescription appetite suppressants like Orlistat and Alli (approved by the FDA), may interact with the diet.
IF isn’t suitable for everyone. For instance, it’s not recommended for people who are breastfeeding, as they have specific nutritional needs. It’s also not advisable for those with a history of eating disorders.
Remember, maintaining a healthy weight isn’t just about diet. It’s also about lifestyle changes like regular physical activity, adequate sleep, and stress management. And while IF can be a useful tool, it’s not a magic bullet. It’s just one piece of the puzzle in achieving and maintaining a healthy lifestyle.
As always, it’s important to research and consult with a healthcare provider before starting any new diet or lifestyle change.