Metabolism is a term used to describe the reactions that occur within your cells to provide your body with the energy needed for vital processes such as development, movement, and growth.

Your metabolic rate is the energy your body uses throughout the day to function and perform tasks like exercising and digesting and processing the food you eat. Several factors determine metabolic rate, including your age, gender, activity levels, underlying medical conditions, and more.

Following a balanced diet high in nutritious foods and staying active can help you maintain a healthy metabolic rate, which can support optimal body weight and reduce your risk of developing metabolic conditions like diabetes. While no one food can significantly boost your metabolism, studies show certain foods, including some spices, may slightly increase your metabolism and help you burn more calories during the day.

Hot peppers, like chili peppers, are high in powerful phytochemicals that have cellular-protective and anti-inflammatory effects. 

Capsaicin is a major alkaloid compound found in chili peppers and chili powder that’s responsible for the pepper’s spicy flavor. Capsaicin has potent anti-inflammatory and antioxidant properties and may also affect metabolism. For example, studies show capsaicin may increase energy expenditure and fat oxidation (fat burning).

One study found that participants who took 4 milligrams of capsaicin daily for 12 weeks lost 5.91% more body fat than participants taking a placebo treatment. The researchers suggest capsaicin may work to reduce body fat by increasing fat burning, increasing energy expenditure, and reducing appetite.

Studies investigating the effect of spicy food consumption on body weight and metabolism haven’t found that same benefit. One study of over 6,000 people found that people who ate more chili peppers had higher body mass indexes (BMIs) and a greater likelihood of obesity compared to people who didn’t eat chili peppers.

More research is needed to understand how chili peppers, chili powder, and capsaicin affect metabolism and body weight. 

Cinnamon is a popular spice derived from the bark of several species of cinnamon trees, including Cinnamomum aromaticum, or cassia cinnamon, and Cinnamomum verum, or ceylon cinnamon. It contains several health-promoting compounds, including cinnamaldehyde, an essential oil concentrated in cinnamon that may affect metabolism. 

Cinnamaldehyde has been shown to increase calorie expenditure and thermogenesis, a process in which glucose (blood sugar) and fatty acids are broken down to maintain body temperature.

One review of 12 studies found that taking cinnamon supplements in doses of 2 grams or more daily for at least 12 weeks significantly reduced fat mass, waist circumference, BMI, and body weight.

Cinnamon supplementation has also been shown to lower blood lipid levels and promote healthy blood sugar regulation, which can help improve metabolic health and protect against conditions like diabetes and heart disease.

Ginger root has a warm and spicy flavor and is a popular ingredient in sweet and savory dishes, such as baked goods and curries.

Consuming ginger regularly may improve metabolic health by reducing appetite, enhancing thermogenesis, and inhibiting fat absorption in the digestive tract. Research suggests certain compounds found in ginger, including 6-gingerol, act on the body to boost thermogenesis, supporting fat loss.

One review found that ginger supplements significantly decreased body weight and waist-to-hip ratio in people with overweight or obesity. Your waist-to-hip ratio compares your waist and hip circumferences. A lower ratio indicates lower belly fat. Higher belly fat is associated with metabolic syndrome, a group of symptoms like high blood sugar and high cholesterol that increase your risk for conditions like heart disease and stroke.

Although these findings are encouraging, not all studies have found ginger effective for boosting weight loss or fat burning. More research is needed to understand how ginger influences metabolism.

Turmeric is a brightly-colored spice that contains a pigment called curcumin. Curcumin is the main active component of turmeric and has been shown to increase energy expenditure and inhibit adipogenesis, or the creation of fat cells.

Curcumin activates certain pathways in the body, including the AMP-activated protein kinase (AMPK) signaling pathway, which stimulates fat burning and decreases fat accumulation. Supplementing with curcumin may improve metabolic health by enhancing weight loss and decreasing body fat levels.

One umbrella review of 14 systematic reviews and meta-analyses found that curcumin supplementation significantly reduced BMI, body weight, and waist circumference.

Another review of 60 studies found that supplementating with curcumin or turmeric significantly reduced body weight, BMI, waist circumference, and body fat percentage. It also found that curcumin and turmeric increased levels of adiponectin, a protein that regulates processes like fatty acid breakdown. Low levels of adiponectin are associated with metabolic conditions like obesity and diabetes.

Cumin (Cuminum cyminum L.) is a spice commonly used in Indian, African, Mexican, and other cuisines. Though research on its mechanism of action is limited, some studies suggest that cumin may increase fat burning and reduce appetite.

• One review found that cumin supplements in doses ranging from 25-2,000 milligrams per day for 8-24 weeks were effective for reducing body mass index and waist circumference. The cumin treatments also helped reduce blood lipid levels, including LDL cholesterol.
• One study of 72 overweight people found that participants who consumed 75 milligrams of cumin and lime twice daily for eight weeks lost significantly more body weight and had significantly lower blood sugar and blood lipid levels. This study used cumin powder and lime in combination, so it’s unclear if cumin would have had the same effect if used alone.
• An older study found that women considered overweight or obese who consumed 3 grams of powdered cumin with yogurt twice per day for three months as part of a low-calorie diet experienced greater reductions in body weight, BMI, and waist circumference compared to women who only consumed plain yogurt.

Though cumin may positively affect metabolic health, including body weight, research in this area is limited, and it’s currently unclear how an average dietary intake of cumin impacts metabolism.

Saffron is a spice derived from the saffron crocus flower (Crocus sativus L.). Supplementing with saffron may improve metabolic health by activating pathways that regulate body weight and glucose homeostasis, including the AMPK pathway and the glucose transporter type-4 (GLUT-4) pathway.

A small study of 32 women with obesity and type 2 diabetes had one group of women take 400 milligrams of saffron powder per day and participate in three weekly aerobic training sessions for eight weeks. Another group took a placebo supplement and also participated in aerobic training.

• The saffron plus aerobic training group lost more body weight and body fat and had significantly lower blood sugar and LDL levels than the placebo and aerobic training group.
• The women who combined aerobic training and saffron supplementation also experienced greater increases in a hormone called irisin, which plays an important role in metabolic processes, such as regulating energy expenditure and blood sugar and insulin levels.

These findings indicate that adding saffron to your diet may support a healthy metabolism. However, more research is needed to confirm if a saffron-rich diet would have a measurable impact on body weight and other markers of metabolic health. 

Though other spices may impact metabolism by increasing fat burning and boosting energy expenditure, human evidence is limited.

Findings from research studies conducted in animals and test tubes suggest that spices such as fenugreek, cardamom, and black pepper may increase metabolism, but human evidence is lacking.

Also, many studies investigating the effects of spices on metabolism focus on the individual components of spices, such as piperine found in black pepper and curcumin found in turmeric, rather than the whole spice.

Many spices offer other benefits, such as reducing inflammation and improving heart disease risk factors. Incorporating a wide variety of spices in your diet is a simple way to help improve and protect overall health.

While adding certain foods to your diet, like spices, may positively affect metabolic health, changing your overall diet and lifestyle is more effective for improving metabolism, body weight, and disease risk. Here are some recommendations:

• Diets high in protein and composed of nutritious, whole foods are more likely to increase energy expenditure than diets low in protein and high in ultra-processed foods. Proteins require more energy to break down than carbs or fats.
• Exercise, including resistance training, can increase muscle mass, improve fat burning, and significantly reduce metabolic disease risk.
• Getting the recommended 7-9 hours of sleep per night and managing stress can support metabolic health.
• Addressing underlying health conditions that may affect metabolism and body weight, such as thyroid conditions, is also critical.

Whether you’re trying to lose weight or improve your overall metabolic health, it’s always best to use evidence-based methods, such as following a nutritious dietary pattern, increasing physical activity levels, and prioritizing sleep and mental health to support a healthy metabolism. 

Though many factors, such as age and gender, affect metabolic rate, dietary choices can have an impact, too.

While research is generally limited, some study findings show that incorporating certain spices into your diet, such as chili pepper, turmeric, and cinnamon, may positively affect metabolism. 

However, the most important factors in maintaining a healthy metabolism include following an overall nutritious diet, getting enough physical activity, managing stress, getting proper sleep, and addressing underlying health disorders.