We often hear people blaming their weight on metabolism, or how their body burns calories and breaks down food into energy. While some complain about how they barely eat anything but still gain weight, others boast saying they can eat whatever they want and keep their weight under check, all thanks to a fast metabolism.
So, does metabolism actually play a role in weight gain or weight loss? And if yes, is there a safe and/or natural way to speed up a slow metabolism? Also, what about the pills that we see in the market? Are they effective, or even safe?
First things first
Metabolism is much more than a buzzword; it is the body’s ‘engine room’, constantly converting food into energy to keep us alive and functioning. Dr Nisha Kaimal, consultant, endocrinology and diabetology, Kokilaben Dhirubhai Ambani Hospital, Mumbai, explains: “Metabolism refers to the sum of all complex (chemical) reactions that occur in the body to provide it with energy. This energy is used for vital processes such as breathing and circulation and for synthesis of new organic material.”
Metabolism is all about the processes that convert food into energy and the raw materials needed for growth, maintenance, and repair. These processes are broadly divided into catabolism (breakdown of larger molecules to release energy) and anabolism (reverse process by which the body utilises the energy released by catabolism to synthesise complex molecules). Another factor is the basal metabolic rate (BMR)—the amount of energy the body needs to perform its most essential functions while at rest. It is the body’s major source of energy expenditure and is affected by various factors such as muscle mass, age, sex, race, exercise, diet, and medical conditions. A faster metabolism means your body uses energy more quickly, while a slower one means it uses energy more slowly.
Dr Ashok Kumar Jhingan, senior director, centre for diabetes, thyroid, obesity & endocrinology at BLK-Max Super Speciality Hospital, Delhi, adds, “It’s a complex network of biochemical reactions that occur within cells, involving the breakdown and synthesis of organic molecules such as carbohydrates, proteins, and fats.”
Balance is the key
Contrary to popular belief, metabolism is not the sole reason behind weight gain or loss, say experts. “While metabolism influences how quickly one burns calories, weight is ultimately a balance of calorie intake versus total energy expenditure. Weight gain usually happens when one consumes more energy (food) than the body needs to maintain its current weight. People with slower metabolisms might burn fewer calories at rest, but overeating and lack of adequate exercise are more significant contributors to weight gain,” says Dr Kaimal.
Factors beyond metabolism which affect weight include lifestyle factors such as physical activity, diet, sleep, stress, hormones, genetics, medications and even medical conditions.
Many people believe that metabolic disorders cause weight gain or decrease, says Dr Sandeep Kharb, senior consultant, endocrinology, Asian Hospital, Faridabad. However, he points out that metabolism naturally regulates itself to fit your body’s individual requirements. In many circumstances, if your body burns more calories than you consume, you will lose weight (and vice versa). However, various factors influence how many calories your body requires, many of which are difficult to anticipate or determine, says Dr Kharb.
A natural boost
Irrespective of the weight factor, metabolism is intrinsic to life’s sustenance. Dr Kharb says these chemical reactions occur in your body’s cells every second, adding that the mechanisms enable you to breathe, move, and heal. Several cultivated healthy habits can enhance metabolism, say doctors. And muscles are of prime importance. Muscles burn more calories than fat, even while at rest. More the muscle in the body, the higher is the metabolic rate. Thus, strength training and resistance exercises to help build and maintain muscle are important to boost metabolism, suggests Dr Kaimal.
High intensity interval training (HIIT) exercise should also be included in the workout regime. It boosts metabolism both during and after the workout. Cardio exercises like running, swimming, cycling or skipping burn calories and increase energy use. Non-exercise activity thermogenesis (NEAT), like walking or standing, contribute further. These activities are important for people who cannot undertake intense exercise.
Another aspect is eating enough protein, which needs more energy to digest, and can temporarily raise metabolism through the thermic effect of food. Staying well-hydrated is also important and so is managing stress, and avoiding long-term calorie restriction. “Even minor dehydration might impair your metabolism,” says Dr Kharb.
Dr Jhingan of Max says a balanced diet that includes protein-rich foods, whole grains, and healthy fats and certain nutrients like vitamin D, iron, and selenium should be prioritised.
“Eat well-balanced meals on a regular basis. Do not skip meals. Your metabolism performs best when it has a consistent supply of energy. Choose fresh produce, lean proteins, complete grains, and healthy fats,” says Dr Kharb, as he also warns against random and excessive diets. “Extreme calorie restriction or extended fasting might slow your metabolism and cause your body to retain energy.”
And last but not the least, getting quality sleep is essential as poor sleep slows metabolism and leads to unhealthy food cravings. “Lack of sleep can affect your hormones and impair your body’s capacity to use energy efficiently,” says Dr Kharb.
Sizing up quick fixes
Caffeine and green tea are among the most popular metabolism boosters touted in popular health advice but do they really work? “Caffeine stimulates the central nervous system which can increase energy expenditure temporarily,” explains Dr Kaimal, adding: “The increase in metabolism can last for up to three hours after consumption. But the effect is temporary, hence, it is not substantial to be used as a primary weight loss strategy.”
Green tea contains caffeine and certain phenolic compounds that act as antioxidants and its extracts or drinks can slightly increase metabolism and calorie burning. Catechins in green tea may enhance fat oxidation. “However, these effects are usually modest and vary between individuals,” Dr Kaimal notes. She advises that these are best used as part of an overall healthy routine especially if the person is physically active, well hydrated and eating balanced nutritious meals, at the same time warning, excessive consumption can lead to jitteriness, sleep issues, and digestive problems.
Dr Kharb adds that green or oolong teas may impact gut microbiota potentially improving fat metabolism but cautions that prior research suggests that these teas have little effect on metabolism, and are even conflicting.
A bitter pill to swallow
Today, the supplement market is flooded with pills promising to rev up your metabolism. But are they effective or even safe? “There are many supplements marketed as metabolism boosters, often containing caffeine, green tea extract, capsaicin, or other herbal blends. While some may temporarily increase metabolic rate, the results are generally very minor and inconsistent,” says Dr Kaimal.
The real risk lies in their unregulated nature. “Many of these products are unregulated, there is no scientific evidence to back the claims, and their safety is questionable. Some have been linked to heart issues, high blood pressure, liver damage, or mood changes,” points out Dr Kaimal.
“One must always consult a healthcare provider before using any supplements. Safe and positive effects on metabolism come essentially from simple lifestyle choices, and not pills,” she emphasises.
Dr Jhingan of Max also says that their safety and efficacy are often questionable as some may contain stimulants, herbs, or other substances that can interact with medications or have adverse effects.
Dr Kharb, too, dismisses the trend outright and says none of them truly increase metabolism. “There are two safe and simple techniques to boost metabolism: eating a healthy breakfast and physical exercise.”
For a fitter you
- Building lean muscle through resistance training is vital; lifting weights thrice a week has beneficial effect on metabolic rate
- Short, intense exercise sessions like HIIT, aerobic exercises, strength training can raise metabolism
- Regular exercise impacts metabolism by improving insulin sensitivity, boosting calorie burning, increasing body’s ability to use fat for fuel
- Eat balanced meals with adequate protein, whole grains, and healthy fats
- Avoid excessive sugar and processed foods
- Avoid going on extreme/fad diets; or prolonged fasting
- Drink enough water; it is essential for all metabolic reactions
- Sleep for 7 to 8 hours; stress management is important
- Avoid sitting for prolonged periods at a stretch