Many individuals struggle with a slow metabolism, which can make shedding excess kilograms feel like an uphill battle. The good news is, there are actionable steps you can take to rev up your metabolism and kick-start your weight loss journey. In this article, we'll delve into the science behind metabolism, explore common factors that may be slowing it down, and provide practical strategies on how to boost metabolism.
Here’s what we will talk about:
· Works
Addressing whether one can accelerate metabolism—like the impact of increased water intake on calorie expenditure throughout the day, the metabolic activity of muscle, and the alleged metabolism-boosting effects of green tea and spicy foods—raises pertinent questions. Additionally, there's curiosity surrounding the influence of sauna sessions, cold exposure, reverse dieting, and cardio on metabolism. But before delving into these topics, let's align on the concept of metabolism within a fitness framework, referring to metabolic rate or total energy expenditure.
What is Metabolism
Essentially, it's about understanding how many calories the body burns daily. Research underscores the remarkable individual variability in metabolic rates, as illustrated by a comprehensive study published in Science. This study showcased diverse metabolic rates among over 6,000 individuals of similar demographics, highlighting significant differences in daily energy expenditure. At a standardized weight, individuals exhibited varying calorie burns, from as low as 1,400 to as high as 5,700 calories per day. This divergence prompts the inquiry: Can strategies be employed to boost metabolism, particularly for individuals with purportedly slower rates? Enhancing metabolism not only enables the consumption of more calories during weight loss efforts but also impacts performance and muscle retention positively. Let's categorize various strategies into those proven effective, those with potential, and those unlikely to significantly impact metabolism.
Probably Doesn’t Work
Now, let's talk about green tea. Despite widespread claims linking green tea to metabolism boosts of up to 8%, scientific evidence tells a different story. A 2021 systematic review found that out of four studies examining acute metabolic effects, three showed no significant impact, while one reported a mere 79-calorie increase in daily energy expenditure. However, this finding was based on a small sample size of 10 subjects and a short duration of 24 hours, limiting its reliability. Moreover, two studies investigating green tea's long-term effects on fat loss found no substantial benefits. Consequently, while green tea may offer a slight metabolic boost, it doesn't seem to translate into significant fat loss over time.
Now, let's explore the sauna's impact. Many associate sweating in the sauna with increased calorie burning. However, a 1995 study from Japan observed a mere 20 to 25 beats per minute rise in heart rate and oxygen consumption during sauna use, equating to approximately 19 extra calories burned in a 10-minute session for an 80 kg individual. Comparatively, sitting in a standard room burns around 14 calories in the same duration. Thus, the difference amounts to a negligible five calories, akin to consuming a stick of gum.
Certainly, cold plunges and ice baths have gained popularity on social media, but do they truly elevate your metabolism? While sitting in a cold bath does increase oxygen consumption and induce shivering, indicating a metabolic uptick, the actual calorie expenditure is rather underwhelming. A 10-minute soak in an ice bath burns approximately 28 calories, compared to the 14 calories expended while sitting at room temperature. Hence, the metabolic boost from cold baths is marginal.
Moving on to meal frequency – does consuming more meals throughout the day stoke the metabolic furnace? It appears not. A study conducted in 2012 had participants spend three days in an isolated respiration chamber, consuming either three or fourteen meals per day with identical total calorie counts, revealing no variance in energy expenditure. Similarly, a meta-analysis from 2015, amalgamating data from 15 studies, found no significant difference in fat mass across various meal frequencies. Despite a potential advantage for higher meal frequencies, this result is skewed by a single study, as noted by the authors.
Might Work
Let's begin with water. Does increasing water intake boost metabolism? Yes, but only marginally. Each glass of cold water you drink burns approximately eight calories because your body expends energy to warm the water to body temperature. Cold water offers a slightly larger metabolic boost compared to room-temperature water. However, despite this modest calorie burn, we categorize water intake as a strategy that might work, but with reservations. While loading up on water seems logical for enhancing fat loss, its real-world effectiveness is debatable. The extra calories burned from increased water consumption could potentially be offset by subconscious reductions in physical activity. Moreover, excessive water intake within a short period can lead to water intoxication or hyponatremia, posing health risks. Generally, aiming for 8 to 12 glasses (about 2 to 3 liters) per day suffices, guided by internal thirst cues. Although water can promote satiety during meals, helping control daily calorie intake, it's essential to avoid excessive consumption.
Next, let's discuss the impact of spicy foods, exemplified by a bowl of green curry chicken and rice. Green curry's fiery kick comes from ingredients like ginger, garlic, lemongrass, and chili peppers. Among these, chili peppers stand out due to their capsaicin content, a compound with documented thermogenic properties. A 2017 meta-analysis of nine studies revealed that capsaicin increased energy expenditure by an average of 69 calories per day, particularly noticeable in individuals with a BMI over 25, classifying them as overweight. In this serving of green curry, approximately 0.5 grams of chili pepper contribute around two milligrams of capsaicin. Extrapolating from the meta-analysis, this equates to a modest 20-calorie metabolic boost at best, overshadowed by the meal's 700-calorie content. Nonetheless, while capsaicin supplementation might offer a marginal benefit, the primary advantage of spicy food lies in its ability to enhance satiety and fullness. We find that spicy meals encourage slower eating and increased water consumption, potentially reducing overall calorie intake and aiding fat loss. Therefore, spicy food it’s a strategy that might work, albeit with limitations.
Alright, let's delve into reverse dieting, a trend that has gained significant traction in recent years. Reverse dieting entails gradually increasing calorie intake instead of decreasing it, to revive the metabolism. Undoubtedly, we've observed instances where individuals have augmented their caloric intake by several hundred calories while maintaining their body weight. However, our primary reservation with reverse dieting lies in its perceived necessity to progress slowly post-diet. From our perspective, it seems more logical to swiftly transition to the new maintenance calorie level. Subsequently, once this new maintenance level is established, one can incrementally adjust caloric intake further. Eventually, you'll hit the upper threshold of your dynamic maintenance range, prompting weight gain.
Now, let's explore the realm of weighted vests. Recent evidence suggests an intriguing concept involving a system of sensors in the body, called the gravitastat, which detects changes in bone loading. By wearing a weighted vest, your body perceives increased weight and adjusts calorie expenditure accordingly, potentially reducing hunger levels. Anecdotal evidence, like the case study conducted by natural Pro bodybuilder Eric Salazar and exercise scientist James Krieger, demonstrates promising results. Salazar wore na 15 kg weighted vest for 90% of his waking hours during competition prep, achieving an impressively shredded physique with reduced side effects compared to past diets. While weighted vests show promise, we refrain from categorizing them definitively until more research emerges.
Works
Now, let's delve into the topic of building muscle. You've likely heard the adage that muscle burns more calories than fat, and this holds true – three times more, to be precise. At rest, 0.5 kg of fat burns about two calories per day, whereas 0.5 kg of muscle burns about six calories per day. Conducting a quick calculation based on my current body composition reveals that if I were to remain sedentary all day, the fat on my body would burn 24 calories, while the muscle would burn 480 calories, resulting in a notable 456-calorie difference. Now, consider yourself as an example. Suppose you're a relatively new lifter and over the next five years, you gain 15 kg of muscle. If you initially burned 2,500 calories per day, post-muscle gain, you'd burn 2,680 calories per day – a 180-calorie difference. This translates to approximately four extra kiwis you could indulge in daily.
Let's delve into the realm of cardio. While cardio undoubtedly burns calories, research indicates a phenomenon called "Energy Compensation." Essentially, this means that when you engage in cardio and burn more calories, your body instinctively reduces calorie expenditure through non-exercise activities, like fidgeting or shuffling. For instance, if on a typical day, you burn 500 calories through these activities, and then you decide to go for a 30-minute jog, burning another 500 calories, your body adapts by reducing non-exercise calorie burn. Consequently, you might only burn 350 calories through non-exercise activities post-jog. Despite this compensation, cardio still contributes to overall calorie expenditure, albeit to a lesser degree. On average, for every 100 calories burned through cardio, you might only see a 72-calorie increase in daily energy expenditure. Hence, while diet remains our primary tool for creating a caloric deficit, cardio serves as a supplementary method. Even with energy compensation in mind, cardio remains effective at burning calories.
Avoid extreme calorie restriction diets, as aggressive cuts can lead to a decrease in metabolic rate. It's generally advisable to aim for a weight loss rate of 0.5 to 1 percent of your body weight per week, as going beyond this range increases the risk of metabolic slowdown. Slow dieting is proven to be effective.
Incorporate additional non-exercise activities into your daily routine whenever possible. Alongside options like using a weighted vest, simple actions such as parking further from the store, taking the stairs instead of the elevator, and frequently standing up and stretching at your desk contribute to what we like to call "meat smuggling”.
It's essential to note that even if you adopt these strategies and have a relatively slower metabolism, weight loss is still achievable. Research indicates that metabolic rate alone isn't a reliable predictor of long-term weight loss success. Factors such as regular physical activity, monitoring your weight, engaging in weight training, and making sustainable lifestyle changes play more significant roles in achieving lasting weight loss results.
If this were helpful, it would mean a lot if you subscribe to my Newsletter. I love researching and writing about the stuff and sharing everything I find in my Newsletter.
Source: Jeff Nippard.