Despite the countless debates around the best diet for staying fit and healthy, everyone wholeheartedly agrees that you can’t go wrong with protein. While carbohydrates (carbs) and fats are undeniably important for nutrition, we’re about to uncover just how protein helps you burn body fat. But first, we must understand its overall purpose in our diet.
Protein and our Body
Proteins are made of chains of amino acids. Once they are consumed, they’re broken down into the amino acids, to be then used as building blocks for the proteins we need in our body. When our diet isn’t getting enough protein, the body uses the amino acids for organs that are essential for survival. That’s why non-essential tissues, like hair and nails, get weaker (see urban malnutrition).1 An astounding 88% of people in India do not get an adequate amount of protein, which is 0.8 g/kg body weight (or 15-16% of total energy) for a sedentary person. A diet is considered to be sufficient in protein once it exceeds this limit.2 As mentioned previously, fat loss involves losing more calories than you consume (called a ‘caloric deficit’). Protein helps fat loss by promoting satiation (making you feel full faster) and affecting our metabolism. Now let’s take a closer look at both of these.3
Protein and Satiety
Protein is the most satiating macronutrient, followed by carbs and fats. The fact that it makes us full translates to us eating less, which consequently helps with fat loss.
It does so in a bunch of ways, with the help of hormones:3
1] Protein increases the body’s secretion of hormones that encourage satiety (namely GIP, GLP-1 and CKK), and have been shown to reduce people’s food intake and meal sizes. CKK, along with another hormone called leptin, is particularly good at increasing satiety even as we eat – naturally, this decreases the meal size.
2] It reduces the secretion of a “hunger hormone” called ghrelin, which is produced by cells in the gastrointestinal tract typically when the stomach is empty.
3] Some evidence suggests that the presence of amino acids in the blood makes us feel satiated – especially due to one particular amino acid called tryptophan. This is then converted to serotonin, the hormone that uplifts our mood (you know that happy, satisfied feeling after a meal? Thank your serotonin).
4] In high-protein low-carb diets, our body gets its energy from fats. They are broken down into molecules called ‘ketone bodies’ that provide energy and are meant to increase satiation. That’s why these diets should contain sufficient fat ( the good kind of fat).
Interestingly, different types of protein induce their own effects on satiety. One study found that pea protein was a little more effective in suppressing hunger than whey protein, followed by milk protein (which is made up of 80% casein and 20% whey protein).4
Protein and Metabolism
Even when we’re at rest, our body is torching calories to power processes like breathing, keeping your heart beating and maintaining your body’s functions in general. The rate at which this is done is called the basal metabolic rate (BMR). There are a number of ways in which proteins increase the number of calories we burn daily.
1] Protein helps build muscles after exercise, particularly after endurance exercises. Muscle – a very active tissue in our body – uses up calories in order to function. So the more muscle we have, the higher our BMR. Without sufficient protein, muscle tissue will heal after workouts, but its building capacity will be limited.
2] When our body uses food for digestion, absorption, transport, processing and the storage of nutrients, it burns calories – this process is called dietary-induced thermogenesis, or DIT. Protein creates the highest DIT, increasing metabolism by a considerable amount (three times as much as carbs create, and ten times as much as fats!). Since a high-protein diet creates a higher BMR, it would even limit the weight regain that people generally experience after weight loss.5
Protein and our Diet
Having discussed all the advantages of protein, we also need to keep in mind that we must not overdo it. This is because we need to limit our calorie consumption too, and fats and carbohydrates are also important for our wellbeing. So there’s only so much space in our diet for proteins. That’s why a balance is essential. Try and stick to 1.2?g protein per kg body weight per day.2 High protein foods include meat, fish, cheese, tofu, beans, lentils, yogurt, milk, nuts, and seeds. Some vegetables like broccoli and Brussels sprouts are also good sources. These also have carbs, fats and other nutrients, so including these in your diet can help you get all the nutrients you need. When you’re pressed for time, a protein supplement can come in handy as well. There’s clearly plenty of reason to gorge on protein-rich foods – whether you want to shed those extra pounds or simply have a healthier diet!
1. Finner AM. Dermatologic Clinics 2013, 31(1): 167-172.
2. Martens EA, Westerterp-Plantenga MS. Current Opinion in Clinical Nutrition & Metabolic Care 2014, 17(1): 75-79.
3. Pesta DH, Samuel VT. Nutrition & Metabolism 2014, 11: 53.
4. Diepvens K, et al. Int J Obes (Lond) 2008, 32(3): 510-518.
5. Paddon-Jones D, et al. Am J Clin Nutr 2008, 87(5): 1558s-1561s.