Blog Post written by Student Dietitian Dilys Hor
Keen on boosting your metabolism to aid in weight loss? Heard of specific foods or supplements that can help? Wondering if eating six times a day instead of three, or not eating past 8pm helps keep your metabolism high?
Does any of this sound familiar? Read on, as I attempt to dispel some metabolism boosting myths, and give you an idea about what actually works.
Claim: Green tea and chilli peppers can speed up metabolism
The truth: Some high quality studies have indeed shown increased energy and fat metabolism within a 24-hour period after consuming catechins and caffeine (found in green tea) and capsaicin and capsinoids (found in chilli peppers).
A summary of the existing evidence on longer-term effects, such as weight loss and weight maintenance, has showed that these compounds may aid in weight loss and maintenance, especially in overweight individuals.
However, their effects defer with ethnicity (i.e. Asians subjects lost more weight than the Caucasian subjects) and how much caffeine people normally consume (i.e. the more you normally drink, the less significant the effects). The amount of capsaicin and capsinoids consumed in these studies are also too high to achieve by eating chilli peppers alone, meaning capsule supplementation is needed.
Claim: Eating more frequently e.g. 6 small meals vs 3 main meals can increase metabolic rate
The truth: The overall evidence suggests that there is no difference in the amount of energy used across the day between lower and higher frequencies of eating, even while keeping the amount of calories eaten equal for both diets. The amount of weight loss achieved for both eating patterns were also found to be similar.
Claim: Eating after 8pm causes weight gain
The truth: No matter the timing, eating more energy than your body uses will cause weight gain. In recent years, some evidence from healthy men has shown that eating or drinking small protein-rich meals 30 minutes before bed may raise morning metabolism, improve overnight muscle protein building and decrease hunger the following morning.
Interestingly, a study on overweight and obese women found that having a cup of cereal and milk 90 minutes post-dinner led to lower daily caloric intake and modest weight loss over 4 weeks. While another study also noted a decrease in next morning’s appetite after eating a snack 30 minutes prior to bed, it found unfavourable metabolic effects in sedentary overweight and obese women.
Though more extensive research is needed, this shows thatpeople of different ages, genders, weights and activity levels have vastly different needs – eating before bed may be beneficial for some, but not others.
So what ACTUALLY works?
Rather than spending hundreds on supplements or diet pills, or drinking eight cups of green tea a day to boost your metabolism to lose weight, focus on:
- Eating a healthy diet with appropriate portions
- Making exercise a regular part of every day, including strength training as part of your exercise routine
- Getting enough sleep