Last night was the Lululemon and FW Nutrition event, and the question “does eating more frequently (snacking) speed up the metabolism?” Rather than just answering this question I decided to take a look at what the research says about snacking, why your metabolism slows at all and ways in which you can increase it.
Your metabolism is the constant process your body uses to keep everything functioning well. It is responsible for making and burning energy from food as well as helping you digest, breathe, staying cool in the heat and warm in the cold and much more.
There is little scientific evidence proving that eating small frequent meals does speed up your metabolism. In fact, after reading many studies it appears the relationship of snacking with weight is inconclusive (1). Some studies did however show that for certain people eating small well-balanced snacks decreased their overall hunger, which resulted in prevention of overeating.
So, should you snack?
This is going to depend on the individual person. Although the research doesn’t support that snacking will speed up the metabolism, snacking still has its place in the diet. Eating small, frequent meals may help stabilise blood glucose levels preventing the 3pm slump. And as mentioned above it could also prevent over eating or mindless eating throughout your day.
Ideally your snacks should include a protein, fibre and good fats. A small tub of Greek yogurt with a sprinkle of nuts and fruit may be the perfect option to keep you going until dinner. Remember a snack is a snack, not a meal. So, for example a serving size of almonds is roughly 12 per serving. Be sure not to over eat here, if weight loss is the end goal.
What can cause a slow metabolism?
Sleep deprivation– Sleep is connected to many hormonal and metabolic processes in the body and is important in maintaining metabolic homeostasis (2). Tthere is growing evidence showing that sleep loss and sleep disorders have a significant impact on the metabolism. So are you getting enough sleep?
Alcohol -For individuals consuming above 12.5 kcal/kg/day of alcohol (that’s basically any alcohol beverage), alcohol accelerates metabolism and decreases fat mass and leptin levels in the body, and the total caloric intake largely exceeds the normal (7). Alcohol also decreases testosterone in the body, which is an important hormone in both men and women that not only regulates the libido but regulates bone mass, fat distribution, muscle mass and strength. Alcohol also depletes B vitamins in the body, which are essential for a fully functioning metabolism.
Stress– Chronic stress can lead to dietary over-consumption (especially palatable foods), increased visceral adiposity and weight gain. The constant activation of the stress response can be interpreted as living in a constant unsafe situation. Historically our chronic stress response was in relation to war, famine, and needing to go long periods of times without food. Now a days it’s often financial, work or relationship concerns. For which it is beneficial for our body to store central (easy to use) fat and glycogen in the liver and hence, help supply the brain with energy on short demand (3).
Fad diets– Yep we have all heard that fad diets are a short-term fix, and this my friends is true. If you drastically decrease your calorie intake, initially you will experience weight loss and perhaps even feel like your metabolism has sped up. But after time your body will compensate for this “starvation mode” which will slow your metabolism. The other problem that can occur when dieting, particularly if jumping from one to the other is that your energy consumption may not be consistent and again this can cause the metabolism to slow.
Obesogenic environments –Obesogens refer to a foreign chemical compound that disrupts normal development and balance of lipid metabolism which can lead to weight gain. Now although it leads to weight gain there is still yet to be more research preformed in this area before knowing its exact effects on the metabolism. Watch this space.
Menopause- Like the rest of your body, your metabolism will go through the ageing process and start to slow as we age, particularly in menopausal women. This is when your nutrition and exercise choices become more important than ever. The change in the hormonal environment at menopause is associated with an increase in total body fat and an increase in abdominal fat. There is strong evidence that oestrogen therapy may partly prevent this menopause-related change in body composition. However, further studies are required to identify the women most likely to gain metabolic benefit from menopausal hormone therapy in order to develop evidence-based clinical recommendations (4).
How to boost your metabolism:
Workout– In particular strength base exercises that help increase your skeletal muscle mass. Skeletal muscle is a crucial tissue for maintaining blood glucose control and energy balance. According to one study muscle may also produce a factor that regulates food intake. This feedback to the CNS (central nervous system) could be via a direct muscle-brain axis through an unknown myokine, although not necessarily a peptide, or an indirect mechanism by muscle signals acting on another tissue that relays satiety signals to the brain (5). And here we were thinking strength training makes you hungrier when in fact it could have the opposite effect.
Hydrate - Increased hydration leads to body weight loss, mainly through a decrease in feeding, and a loss of fat, through increased lipolysis. In rodent studies, the effect is clear and consistent that hydration keeps your metabolism ticking along nicely (6).
Eat well 80% of the time– Given what we have talked about today, what works for one person may not work for the next. And what worked for you 10 years ago, may not work for you now due to the ageing process of the metabolism and changes in your environment. It is recommended to eat a well-balanced diet containing protein, carbohydrates and good fats for at least 3 meals per day. 20% of the time have foods you enjoy but remember not to overdo it.
I hope this article has answered your questions on the metabolism and If you are have any concerns with weight management or dis-ease in the body please speak to your health practitioner or click the link below to get in touch with me one on one.
1. Berteus Forslund H, Lindroos AK, Sjostrom L, Lissner L. Meal patterns and obesity in Swedish women-a simple instrument describing usual meal types, frequency and temporal distribution. Eur J Clin Nutr. 2002;56:740–747.
2. Sunil Sharma, Mani Kavuru. Sleep and Metabolism: An Overview. Int J Endocrinol. 2010; 2010: 270832. Published online 2010 Aug 2. doi: 10.1155/2010/270832
3. Cristina Rabasa, Suzanne L, Dickson. Impact of stress on metabolism and energy balance. June 2016, Pages 71-77
4. Understanding weight gain at menopause. Women's Health Research Program, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia. 2012 Oct;15
5. Alexandra C. McPherron, Tingqing Guo, Nichole D. Bond, Oksana Gavrilova. Increasing muscle mass to improve metabolism. 2013 Apr 1; 2(2): 92–98. Published online 2013 Apr 1.
6. Simon N. Thornton. Increased Hydration Can Be Associated with Weight Loss. Front Nutr. 2016; 3: 18. Published online 2016 Jun 10.
7. De Timary P, Cani PD, Duchemin J, Neyrinck AM, Gihousse D, Laterre P-F, et al. (2012) The Loss of Metabolic Control on Alcohol Drinking in Heavy Drinking Alcohol-Dependent Subjects. PLoS ONE 7(7): e38682.