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Coffee is one of the world’s most beloved and widely consumed beverages. People drink over 160 million bags of coffee globally per year. Many relish coffee for its energizing effects from caffeine. But beyond just a pick-me-up, emerging research suggests coffee may offer potential weight loss benefits as well.
Several recent studies have delved into connections between coffee drinking and weight changes, yielding intriguing but sometimes mixed results. While coffee demonstrates promise in supporting weight management, there are some important nuances regarding how it is consumed.
Overview of Coffee and Weight Loss Research
In October 2023, an extensive study published in the prestigious journal The American Journal of Clinical Nutrition took a deep dive into coffee and weight by analyzing pooled data from over 155,000 adult participants in three major long-term health studies – the Nurses’ Health Study, Nurses’ Health Study II, and the Health Professionals Follow-Up Study.
The researchers found that increased consumption of unsweetened coffee was associated with modest yet significant weight loss over time, while adding sugar to coffee seemed to negate the benefits and was linked to slight weight gain. Specifically, they discovered that each additional daily cup of plain black coffee was tied to around a 0.12 kg (0.26 lb) reduction in body weight when measured over four years.
Meanwhile, adding just a teaspoon of sugar into coffee daily equated to roughly a 0.09 kg (0.2 lb) weight gain over the same four year timeframe. The effects appeared stronger among younger people under age 40 and those considered overweight or obese with BMIs of 25 and higher.
Other smaller studies covered in journals like Obesity and Appetite have investigated coffee’s impact on appetite, hunger levels, and calorie consumption, with conflicting results. Some research indicates coffee may mildly suppress appetite thanks to influences on hormones like ghrelin.
However, other studies have not found a statistically significant effect on reducing appetite or calories consumed at meals. This suggests coffee’s effects vary considerably between individuals based on age, weight, caffeine tolerance, and genetics. More research is needed to draw firmer conclusions.
Unsweetened Coffee Linked to Modest Weight Loss
One primary weight loss advantage of plain unsweetened coffee is that it contains minimal calories. So it can easily fit into a calorie deficit needed for dropping excess pounds without adding excess energy.
According to registered dietitian Ashley Shaw, a typical 8 oz cup of black coffee brewed at home has less than 5 calories. For those tracking calories for weight loss, coffee is an ideal beverage choice that satisfies a craving without derailing diet goals.
In comparison, a medium 16 oz Starbucks Caffe Mocha has 400 calories – nearly a quarter of some dieters’ daily calorie allotment. Iced coffee drinks fare little better, with a 16 oz Java Chip Frappuccino providing 390 calories.
Beyond being naturally low-calorie, coffee may also enhance weight management through other mechanisms like boosting metabolism thanks to its caffeine content. As a stimulant, caffeine is one of the only substances scientifically shown to increase resting metabolic rate, meaning the rate at which the body burns calories for energy while at rest.
Research has found that caffeine consumption – such as through coffee drinking – can enhance thermogenesis in the body, which is the process of heat production that expends energy. Caffeine also promotes fat oxidation or breakdown for fuel. Over time, studies observe that habitual coffee drinkers tend to have slightly higher daily metabolic rates.
However, there is an important caveat – with regular exposure, the body builds up a tolerance to caffeine, meaning its impacts on metabolism diminish over the long haul. People who drink coffee every day may see less metabolic enhancement than more sporadic or new consumers.
Added Sugar in Coffee Can Lead to Weight Gain
While plain black coffee in moderation, can support healthy weight goals, the story changes dramatically when significant calories are added via sugars, creams, and calorie-laden flavours.
Just a single teaspoon of added granular white sugar contains around 15 calories and 4 grams of carbohydrates. When sugar is added to coffee – or any beverage – these calories can quickly multiply while providing only empty nutritional value without benefits like fibre, protein, vitamins, or minerals.
Popular coffee drinks are prime examples of how sugar can turn coffee from low-calorie to high-calorie. For instance, a 16 oz Starbucks Caffe Mocha has 50 grams of sugar and 400 calories. Their 16 oz White Chocolate Mocha packs an even heftier 540 calories and 64 grams of added sugar.
Espresso drinks fare a little better – a 16 oz Caramel Macchiato from Starbucks contains 250 calories and 33 grams of sugar. Even an unsuspecting 12 oz Cafe Vanilla Frappuccino has 50 grams of sugar and 300 empty calories.
As registered dietitian Ashley Shaw points out, these coffee-based beverages “can quickly become high in calories, sugar, and fats when different milks and sugars are added.” The excess calories make it challenging to maintain the calorie deficit required for shedding pounds.
To keep coffee as part of a weight loss strategy, it’s wise to avoid pumping up drinks with added syrups, whipped creams, and sweeteners that can transform an innocent 5-calorie beverage into a 400+ calorie indulgence.
Caffeine’s Effects on Metabolism and Appetite
Two of the main proposed mechanisms behind coffee’s potential benefits for weight management are increased metabolism and lowered appetite. But the research is still emerging in these areas, and some findings remain inconclusive.
Some small studies, like a 2014 trial published in the journal Appetite, have found evidence that coffee may significantly lower levels of the “hunger hormone” ghrelin. This reduction in ghrelin may dampen and suppress appetite.
However, not all human studies have managed to reproduce coffee’s appetite-blunting effects across populations. Other trials uncovered no statistically significant differences in either ghrelin levels or perceived hunger and appetite between coffee drinkers and abstainers.
Clearly, much remains unknown regarding how coffee influences appetite and how effects might vary between individuals or groups. Genetics, age, stomach sensitivity, and other factors likely impact responses.
Regarding metabolism, as previously mentioned, research confirms caffeine can temporarily rev up metabolic rate and calorie burning after consumption. However, due to tolerance over time, these effects do not seem to persist in the long term among habitual coffee consumers.
According to registered dietitian Lon Ben-Asher, “Caffeine intake speeds up metabolism, likely due to the caffeine content. It enhances fat-burning through increased thermogenesis and stimulation of neurotransmitters such as adrenaline.”
Yet overall, caffeine appears to influence individuals rather differently. Some experience pronounced appetite suppression and metabolic surge, while others have minimal response. More research is still needed to understand coffee’s effects on metabolism and appetite fully.
Health Benefits of Coffee
In addition to potential impacts on body weight, coffee may offer a range of other health benefits when consumed in moderation without adding excess sugars or calories.
According to bariatric surgeon Dr. Felix Spiegel, coffee provides “anti-cancer effects because of high concentration of antioxidants. Also, cardiovascular improvements have been demonstrated with controlled intake amounts up to 5 cups daily.”
Coffee beans and the beverage brewed from them are packed with diverse antioxidants that combat oxidative stress in the body. These include polyphenols like chlorogenic acids, melanoidins, and cafestol.
Some research indicates the antioxidants in coffee may help protect cells against DNA damage that can potentially lead to cancer development. This may be one reason habitual coffee intake is linked to reduced risks for certain cancers like liver, uterine, prostate, and colorectal.
Coffee also seems to benefit heart health – studies consistently associate regular moderate coffee drinking with lowered risk of cardiovascular disease. For example, a meta-analysis in The American Journal of Medicine found that consuming 4 cups of coffee daily was tied to a 14% decrease in developing coronary heart disease.
Other large studies reveal those who regularly drink coffee have a reduced chance of stroke, heart failure, and arrhythmias compared to non-coffee drinkers. Coffee may improve heart health by boosting circulation and blood vessel function.
Additionally, studies link coffee to a lower risk of developing type 2 diabetes – a massive review in The American Journal of Clinical Nutrition found that each daily cup reduced diabetes risk by around 7%. Coffee also shows associations with protection against neurodegenerative diseases like Parkinson’s and Alzheimer’s.
Potential Downsides of Coffee
Despite coffee’s diverse potential upsides, it has some drawbacks and cautions to keep in mind. Consuming excessive caffeine can lead to unwelcome side effects like insomnia, anxiety, restlessness, digestive issues, and heart palpitations in sensitive individuals.
Caffeine found in coffee can also negatively interact with certain medications, including antidepressants, antibiotics, diabetes drugs, and blood thinners. Coffee should be avoided altogether by those at risk of bone fractures, as caffeine may mildly increase urinary calcium excretion.
Pregnant women are typically advised to limit coffee intake to less than 200 mg caffeine daily from all sources, as higher intakes have been associated with increased risk of miscarriage, premature birth, and lower birth weights.
Registered dietitian Beata Rydyger notes that poor and inadequate sleep is strongly tied to increased hunger and appetite, particularly for high-calorie junk foods. She cautions coffee drinkers to avoid indulging in late afternoon or evening, which can disrupt natural sleep-wake cycles.
Consuming coffee too close to bedtime can backfire for weight loss by keeping people awake and interfering with crucial overnight hormone regulation that controls hunger cues and metabolism the following day.
Tips for Drinking Coffee to Support Weight Loss
If you want to drink coffee in a way that optimizes potential weight management benefits while minimizing drawbacks, here are some research-backed tips:
Limit Added Sugars and Calories
To reap the benefits of calorie-free, unsweetened coffee, avoid pumping drinks full of added sugars via syrups, whipped creams, and sweeteners that can completely counteract the drink’s low-calorie advantage. If you like a touch of sweetness, try using erythritol, monk fruit, stevia, or other natural low-calorie sweeteners sparingly.
Moderate Your Overall Caffeine Intake
Most experts recommend capping total caffeine from all sources at 400 mg daily max as going above this amount can increase anxiety, insomnia, restlessness, and other side effects in caffeine-sensitive individuals. 4-5 cups of home-brewed coffee should keep intake within moderate range for health.
Avoid Coffee Late in the Day
Since caffeine can linger in the body for hours and disrupt natural sleep cycles, avoid drinking coffee late in the afternoon or evening. To prevent interference with sleep, consume coffee in the morning or early afternoon. Protecting rest is vital for appetite-regulating hormones.
Eat Balanced Meals and Snacks
Pair coffee with nutritious whole foods like oatmeal, eggs, nuts, yogurt, and fruit instead of calorie-laden baked goods. Eat regular balanced meals and snacks to stabilize blood sugar and hunger levels throughout the day.
Stay Hydrated
Drink plenty of water before, during, and after coffee to stay hydrated. Caffeine has mild diuretic effects, so increased water intake helps offset fluid loss. Adequate hydration is key for metabolism and appetite control.
Frequently Asked Questions
Does decaf coffee help with weight loss?
Some research suggests decaf coffee may have appetite-suppressing effects similar to regular coffee, so it can potentially still aid weight loss through reduced calorie consumption. However, without the metabolism-boosting effects of caffeine, the benefits may be more modest.
Is cold brew coffee good for weight loss?
Cold brew coffee contains minimal calories like regular black coffee, so it can support weight loss goals. Some research suggests cold brew coffee may be less acidic and contain more caffeine than hot coffee, but more studies are needed on its health impacts. Avoid adding calories by sweetening or whitening.
Can coffee increase belly fat?
Plain black coffee alone is unlikely to directly increase belly or body fat when consumed without unnecessary added sugars and calories. However, inadequate sleep and disrupted circadian rhythms from excessive late-day caffeine intake can potentially increase appetite hormones like ghrelin, which may indirectly promote fat storage over time.
Does coffee cause anxiety or jitters?
For sensitive individuals, consuming very high doses of caffeine found in coffee, especially when rapidly consumed, can increase anxiety, jitters, tremors, and other unwelcome stimulant side effects. Those prone to caffeine jitters should limit intake to 200-400 mg daily from all sources and spread consumption over several hours.
Is coffee bad for your heart?
In moderation, substantial research suggests coffee reduces the risk of cardiovascular disease in most people. But for those sensitive to stimulants, very high intakes may increase heart rate and blood pressure. As with all foods and beverages, moderation is key when incorporating coffee into a healthy lifestyle.
The Bottom Line
Emerging research indicates that unsweetened coffee may aid modest weight loss through mechanisms like appetite suppression and temporarily increased thermogenesis from caffeine. However, added creamers and especially added sugars appear to counteract these potential benefits. While coffee looks promising for weight management support, it should be consumed in moderation alongside an overall balanced diet and active lifestyle for optimal health. If coffee is not easily available at your location, maybe it’s time to get a good coffee machine.
