The global obesity epidemic, affecting over one billion people worldwide, is largely driven by eating behaviors. Appetite, influenced by both intrinsic and environmental factors, plays a crucial role in weight management. A recent study how exercise affects appetite perception in obese males, shedding light on the physiological mechanisms behind hunger suppression post-exercise.
While exercise is well-known for its benefits in weight management, its direct impact on appetite control has remained a subject of debate. Appetite is regulated by a complex network of gastrointestinal and neurohormonal signals, including hormones like ghrelin, leptin, interleukin 6 (IL-6), and neuropeptide Y (NPY). These hormones influence hunger levels, satiety, and energy balance.
The study published in Physiological Reports examines investigated how moderate continuous aerobic exercise (MICE) alters these hormone levels in obese men, ultimately affecting their hunger perception. The findings reveal that certain myokines and cytokines shift dynamically post-exercise, potentially reducing appetite and offering a promising strategy for weight management.
The study found that after exercise, there was a significant increase in IL-6 and irisin levels in the exercise group compared to those who remained sedentary. These elevated concentrations persisted for an hour after working out. IL-6 has been associated with regulating metabolism and enhancing fat oxidation, while irisin plays a role in converting white fat into more metabolically active brown fat.
Conversely, the study reported a decrease in neuropeptide Y (NPY) levels, a key neurotransmitter responsible for stimulating appetite. The decline in NPY levels post-exercise suggests a temporary suppression of hunger, supporting the idea that exercise can curb cravings. However, the study did not observe significant changes in IL-7 or leptin levels, two other hormones involved in appetite regulation.
Ghrelin, often called the “hunger hormone,” stimulates appetite by increasing activity in specific areas of the brain. Individuals with higher ghrelin levels generally find it harder to lose weight because their bodies signal hunger more frequently.
Research suggests that dieting can lead to an increase in ghrelin levels, making weight loss challenging. Certain medical conditions, such as Hashimoto’s thyroiditis, Prader-Willi syndrome, anorexia nervosa, and bulimia nervosa, are also linked to elevated ghrelin levels, complicating appetite regulation further.
While exercise has clear benefits, the findings should be interpreted with caution. He pointed out that the study had a small sample size, making it difficult to draw definitive conclusions.
Moreover, he highlighted the challenges faced by obese individuals in maintaining an intensive exercise routine. While exercise-induced appetite suppression is promising, consistently engaging in high-intensity workouts may be unrealistic for those who struggle with mobility or fitness levels. More extensive studies are needed to determine the optimal exercise duration and intensity for effective appetite suppression.
Besides exercise, there are several strategies individuals can use to naturally suppress their appetite and improve satiety:
Increase Protein Intake: Protein-rich foods, such as lean meats, legumes, and dairy, promote feelings of fullness and reduce hunger.
Stay Hydrated: Drinking water before meals can help control portion sizes and prevent overeating.
Opt for Fiber-Rich Foods: Whole grains, vegetables, and fruits high in fiber take longer to digest, keeping you full for longer.
Reduce Simple Carbohydrates and Sugars: Simple carbs and sugars cause rapid spikes and crashes in blood sugar levels, leading to increased hunger.
Prioritize Sleep: Poor sleep disrupts hunger-regulating hormones, making it harder to control cravings.
Manage Stress: Chronic stress increases cortisol levels, which can lead to overeating and weight gain.
The study’s findings indicate that moderate exercise can temporarily suppress appetite by altering key hormones. While more research is needed to refine the details—such as optimal workout duration and intensity—this insight adds to the growing body of evidence supporting exercise as a tool for appetite regulation and weight management.
For individuals looking to curb cravings and maintain a healthy weight, incorporating a well-balanced diet alongside regular exercise remains the most sustainable approach. Future studies focusing on larger populations and long-term effects could provide deeper insights into how exercise can be optimized for appetite control, making it an effective strategy in combating obesity.
Exercise alone is not a magic solution for weight loss, but its impact on appetite hormones presents a promising avenue for managing hunger and energy balance. As research continues to evolve, it becomes increasingly clear that integrating physical activity with mindful eating habits can play a vital role in achieving and maintaining a healthy lifestyle.
Credits: PTI
As of November 19, 7am, Delhi's AQI as per the official data stands at 388, however, as per aqi.in, the average AQI of the city stands at 601 at 8.50 am. While there has been data discrepancies, as a result of which, people have come to street to protest against the continuous worsening air quality of the national capital. Amid this, Dr Manan Vora, a Mumbai-based orthopedic surgeon and sports doctor shared some tips to stay safe amid polluted air.
While watching a video of a person cleaning their clogged air purifier, Dr Vora says, "Your air purifiers can change filters but your lungs cannot," and suggests the following 5 tips:
The first tip Dr Vora shares is to create a clean room, which can reduce exposure of pollutants by 60 to 70%. This could be achieved by an air purifier. He suggests everyone to decide one room in the house and shut its doors, and windows during peak hours, and turn on air purifier only in that room. "This alone curbs your exposure by 60 to 70%," he says.
The doctor advises to wear an N-95 mask whenever someone is stepping outdoors. He mentions that a cloth or a surgical mask won't protect them against the pollutants, as N-95 masks are the only protective gears with filters that can keep the pollutants out when you breathe. "Only N-95 blocks the same particles clogging the purifier," he says, referring to a video of cleaning a clogged air purifier's filter.
"Skip your morning walks," he suggests. "AQI is highest at the sunrise and breathing rate triples while exercising. This means you inhale three times more pollution per minute," he says.
This happens because pollutants accumulate overnight, and without wind or sunlight, PM2.5 or the particulate matter stays trapped near the ground, leading to pollution being at its peak by sunrise. As per the data by aqi.in, highest AQI is always registered between 6am to 9am.
Dr Vora suggests that while cleaning your house, instead of dry dusting, use a wet mop, this reduces dust particles. "Dry dusting pushes all the particles back into the air," he says.
The fifth tip he shares is to stay hydrated and consume vitamin C and other antioxidant-rich foods. As per the National Institutes of Health (NIH), US, vitamin C increases resistance to various viral and bacterial infections. A 2007 study published in the Journal of the Royal Society of Medicine noted that vitamin C or its supplement could in fact help patients with pneumonia or other lung-related disease. Thus vitamin C is a good boost for when lungs are at high risk, all thanks to the pollution.
The doctor also suggests the consumption of amla or Indian gooseberry and turmeric to boost your immunity. However, the doctor notes that while they do not cure pollution, but consuming these may reduce inflammation caused by pollutants.
"You cannot fix the AQI of your city, but you can control how much of it enters your body."
Credits: GEMINI
There is a certain satisfaction that comes after powering through a tough HIIT session. You expect that fresh, healthy glow at the end, but some people instead end up with a face that looks bright red, which can make them feel uneasy once they leave the gym.
To help you get back to your favourite spin class or running route without second thoughts, we turned to dermatologists to understand why this happens and how to calm it down. Here is what actually causes that red flush after exercise and what you can do to manage it.
Your face often reddens during a workout because your body sends more blood to the skin and your temperature rises. The blood vessels on your face open wider to help release heat. It is simply your body cooling itself while supplying oxygen to the muscles that are working.
The encouraging part is that a flushed face after working out is usually a normal part of how the body reacts to exertion. As your temperature rises, sweat helps cool you down, but your body also shifts blood flow and widens vessels near the surface of the skin. This can show up as a red or flushed look. Blair Murphy, MD, FAAD, a board-certified dermatologist in New York City, explains that this post-workout redness happens because the small blood vessels in the facial skin open up. The face tends to show it more clearly because it has many surface-level blood vessels.
This kind of flushing appears in certain people simply because they have a greater number of capillaries near the surface. During exercise, your heart pumps faster to carry more oxygen to the muscles. The capillaries expand to move that oxygen efficiently while also carrying heat outward to help regulate temperature.
Your overall fitness level may also play a role. As blood flow increases, skin cells can release different substances in different individuals. Some may release prostaglandins, which add to the redness, while others may release histamines, which can also trigger flushing.
According to Arash Akhavan, MD, FAAD, a board-certified dermatologist in New York City, everyone experiences flushing during exercise, but it is more visible in people with lighter skin because deeper pigment in darker skin tones can hide mild redness. He also notes that some people naturally have a more extensive network of tiny blood vessels, making their skin appear redder after exertion.
Opt for lightweight clothing: You cannot completely stop redness during exercise, but you can take simple steps to reduce it. Try working out in a cooler setting and wear loose, light-coloured clothing to help your body regulate heat.
Avoid alcohol and excessive sun exposure: If your skin already flushes easily, alcohol before a workout is not a good idea. Corey L. Hartman, MD, board-certified dermatologist and founder of Skin Wellness Dermatology, explains that alcohol widens blood vessels and increases facial redness. Too much sun can also irritate the skin and make surface capillaries more visible by causing them to dilate.
Stay away from potentially irritating skincare: Those who flush often or have rosacea should avoid skincare that can irritate the skin further, including alcohol-heavy products, highly acidic creams, or strong retinoids. Dr. Akhavan recommends choosing calming, non-irritating products with ingredients like hyaluronic acid, vitamin C, and niacinamide.
Vitamin C is especially helpful because it protects the skin from oxidative stress and helps shield against UVA and UVB rays, which can intensify redness. Fragrance should also be avoided since it can trigger irritation and increase flushing.
(Credit-Canva)
Researchers at University College Cork, led by Professor Yvonne Nolan, have found key biological reasons why exercise can help protect your mental health, even if you eat a typical Western diet high in fat and sugar. Your diet plays a huge role in keeping your brain healthy. Studies have shown that eating processed foods can increase your chances of developing memory and thinking issues.
However, this one habit can help you keep these issues at bay, according to researchers. The study, published in the journal Brain Medicine, shows that regular running can reduce symptoms similar to depression that are often caused by unhealthy eating. These protective effects involve changes to your gut and hormones.
To figure out how diet and exercise influence the brain, the researchers studied adult male rats for seven and a half weeks. One group of rats ate a standard healthy diet, while the other group ate a rotating "cafeteria diet" of high-fat, high-sugar foods (like ultra-processed meals).
In both diet groups, half of the animals were given a running wheel to exercise freely. This setup allowed the team to clearly see the separate and combined effects of the poor diet and physical activity on the animals' mood and brain.
Voluntary running had an antidepressant-like effect on the rats, even those eating the unhealthy cafeteria diet. This suggests that getting regular physical activity can be helpful for a person's mood, even if they struggle to completely change their eating habits.
While the unhealthy diet didn't severely harm the rats' learning or memory skills, exercise slightly improved their ability to navigate. The researchers also noticed mild anti-anxiety effects from exercise that occurred regardless of what the animals were eating.
The high-fat, high-sugar diet severely messed up the chemicals produced in the gut (called metabolites). The researchers analyzed the contents of the caecum (a part of the large intestine) and found that the unhealthy diet affected 100 out of 175 chemical compounds they checked.
Exercise helped to restore the balance, particularly increasing three metabolites—anserine, indole-3-carboxylate, and deoxyinosine—that are known to be important for regulating mood.
The study did find one complex finding related to brain growth. In rats that ate the standard, healthy food, exercise strongly boosted adult hippocampal neurogenesis (the creation of new brain cells in the hippocampus, the area linked to memory and emotion).
However, the cafeteria diet prevented this usual exercise-induced increase in new brain cells. This suggests that while exercise helps mood regardless of diet, a poor diet might actually stop the brain from fully gaining some of the deepest, cellular-level benefits of physical activity.
This research has important real-world meaning. As an accompanying editorial noted, the fact that "exercise has an antidepressant-like effect in the wrong dietary context... is good news" for people who find it very hard to switch to a perfect diet.
The findings give biological proof that exercise can be an effective tool for improving mental well-being even when facing the challenges of modern, processed foods.
Future research will need to study women and explore longer periods of exercise, but this study provides a strong foundation for using lifestyle changes to support mood and brain function.
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