Can Protein Help You Lose Weight?
Protein can definitely help you to lose weight, but the interesting part is how it does so. Of the three macronutrients: protein, fat and carbohydrates, studies have shown that protein has the most effect on losing weight because of the four effects it has on the body:
When we eat, certain hormone levels in our body change. The level of Glucagon-Like Protein-1 (GLP-1), peptide YY and cholecystokinin increase, while the hormone indicating hunger ghrelin drops. The hypothalamus part of our brain senses these changes and based on the amount of change, tells us when we are full and to stop eating. Protein seems to have a greater effect on satiety than does fat or carbohydrates, so our brain sends out the full signal quicker, thus naturally reducing the total number of calories consumed.
Once we are finished eating, a certain number of calories are burned up to break down and digest food. This is known as the thermic effect. Protein has a higher thermic effect than does fat or carbohydrates. Where 30% of the calories are used to breakdown protein, only 5-10% and 0-3% for carbs and fat, respectively are used. This equates to a net of 70 calories left for every 100 of protein consumed. The other 30 calories are used for digestion.
Partly due to the thermic effect and partly to other factors, protein boosts the number of calories burned in a day by as much as 80 to 100 over what would otherwise have been burned with a lesser protein intake. And the increase in metabolism continues throughout the night while sleeping. The metabolic increase is one advantage diets high in protein have over other diets that are lower in protein.
Appetite Suppression Effect
Because protein takes longer to digest than fat or carbohydrates, a diet with 30% protein keeps one feeling fuller longer, thus reducing the temptation to snack between meals. Not only is the meal-to-meal calories reduced, but studies have shown the whole days’ worth of calories are reduced – by as much as 441 calories per day. Because it takes a calorie deficit of 500 calories per day to lose a pound a week, eating a diet high in protein almost satisfies that deficit requirement alone. Add in some exercise to make up the difference.
Because a diet high in protein not only reduces the number of calories consumed, but also the number of calories burned, it is easy to see why losing weight on a high protein diet is realistic. In one study, participants lost an average of 11 pounds over the 12-week study and the only change they made was adding protein to their diet. While individual results may not be as dramatic, weight loss is possible and should be expected with a high protein diet.
What Are Amino Acids?
Amino acids are the building blocks of proteins found throughout the human body. They band together chemically to form protein strings called peptides and polypeptides. Proteins themselves are classified into two types:
Structural – found in muscle, bones, connective tissue and cell walls.
Functional – included in hormones, the main two of which are insulin and thyroid, as well as digestive enzymes and antibodies.
Within protein, there are over 20 different types of amino acids, broken down into the two main categories of non-essential and essential. While the non-essentials can be created by the body, the essentials cannot, therefore must be ingested as protein from our food. The eight essential amino acids required by adults and their primary functions are:
- Leucine – required for optimal growth and nitrogen balance within the body
- Isoleucine – used to repair muscle tissue
- Lysine – helps the body absorb calcium and form collagen
- Methionine – helps regulate growth and metabolism
- Phenylalanine – assists in the synthesis of other amino acids
- Threonine – used primarily by the nervous system in the production of neurotransmitters
- Tryptophan – used to form serotonin and melatonin both of which enhance relaxation and sleep. Also used to reduce anxiety, depression and help improve the immune system
- Valine – used in the repair of muscle as well as preventing insomnia
Each amino acid has its own function, varying from chemical reactions, to controlling bodily functions, to creating muscle mass and they make up about 75% of our body.
As noted earlier, we need protein each day to maintain good health. Some foods are known as complete proteins as they contain all the essential amino acids. Most of the complete proteins come from animal products including:
- Dairy products
However, there are two plant protein sources that are also considered complete: legumes and soy. On the legume side, dried beans, nuts and nut butters are great essential amino acid sources; tofu, tempeh and soy milk are good soy choices.
This makes it easier for vegans and some vegetarians to get their complete proteins from just plants. Otherwise, they must take an amino acid supplement or combine complementing non-essential plant sources to round out their daily essential amino acid requirement.
While somewhat rare in developed countries, amino acid deficiencies can occur if people are on certain diets low in protein. Symptoms include:
- frequent colds
- constant fatigue
- cuts that take longer to heal than normal
- swelling in the extremities
- slower than normal recovery after a workout
Most people get enough essential amino acids from eating a normal diet containing protein. Amino acids are so important to good health that getting enough each day is critical.
Do Men Need More Protein Than Women?
This question is one of many concerning the difference in nutritional needs between men and women that has persisted throughout the ages. The short answer is yes (in most cases), men do need more protein than women. But why?
A person’s protein need is generally based on two factors: body size and activity level. The Food and Nutrition Board of the Institute of Medicine recommends a daily allowance of 56 grams of protein for men and 46 for women, unless breastfeeding or pregnant. Then the amount jumps to 71 grams per day.
However, it is easy to refine the recommended estimated amount by individual based on the formula of 0.8 grams per kilogram of body weight. If weight is in pounds, divide it by 2.2 to convert to kilograms. So a person weighing 150 pounds would need approximately 54 grams of protein per day. That falls in-between the RDA of the amount listed above.
One of the factors affecting the amount of protein needed each day is activity level. For athlete or those with a high daily activity level, the need increases – up to as high as 2 grams of protein per kilogram of weight. Why the additional protein due to an increased activity level? To keep the body from using lean muscle mass. In the case of our 150-pound individual training for an athletic event, such as an ironman, they would need around 136 grams of protein each day. The additional protein is used for fuel instead of using lean muscle mass.
Not All Protein is Created Equal
It is true, there is a difference where you get protein from. Animal protein is known as a “complete” protein because it contains all of the essential amino acids. Plant protein generally does not, with some exceptions, so vegans and some vegetarians have to ensure they are getting a good mix of plant-based proteins to get all of the essential amino acids or resort to taking protein supplements.
The Dangers of Too Much Protein
One would think that if some protein is good, more is better, but that is not the case. Too much protein can lead to a number of medical issues including osteoporosis. Excess protein is excreted out of the body with urine, but it takes calcium with it, so it is easy to become calcium deficient.
Also, if a lot of protein is coming from red meat, saturated fat can be a problem, leading to cardiovascular issues and obesity. However, staying within the RDA requirements or calculations based on body weight and activity level, will prevent getting too much protein.
While men generally need more protein than women, the difference in most cases is not great. However, factors such as athletic training, breastfeeding or pregnancy can increase a women’s requirement higher than what is it for a more sedentary man.
What Are Complete Proteins and Where Do You Find Them?
Protein is one of three macronutrients and is the one the body uses as its building block. The other two macronutrients are fats and carbohydrates. Humans need protein to repair and grow tissue, digest and metabolize food, produce antibodies to fight infection, and to make the numerous enzymes and hormones that control all of our bodily functions.
But the body can only use protein after it is broken down into the various amino acids. Then it is reassembled into strands of amino acids called peptides and polypeptides and sent throughout the body to do its work.
Our body needs 22 different amino acids to function properly. Of those, adults can produce 13 within the body. These are known as non-essential amino acids. The other 9, known as essential amino acids, the body cannot produce and we must obtain them from our food, namely protein from our food. Foods contain all 9 essential amino acids are considered complete, while foods only containing some of the 9 are incomplete.
Complete Protein Foods
Most complete protein sources are animal-based and include things like:
- Dairy products
While not as plentiful, there are a few plant sources that are also complete, such as quinoa, buckwheat, hemp and chia seeds, spirulina and soy.
Incomplete Protein Foods
The rest of the foods that are plant-based are incomplete because they either lack one or more essential amino acid or the amount they do contain is not sufficient to be labeled as complete. Popular incomplete protein foods within the vegan and some vegetarian circles include nuts and seeds, legumes, grains and vegetables. Just because they are incomplete doesn’t make them bad choices, it just means the food has to be supplemented or two foods combined to add in what is missing.
When combined with incomplete protein, these protein sources make the combination complete:
- Rice added to various beans or other legumes
- Almonds topped over a spinach salad
- Hummus spread on a whole-grain bread or cracker
- Whole-grain noodles combined with peanut sauce
The suggested combinations don’t necessarily have to be eaten together, but can be consumed throughout the same day. But since the body does not store essential amino acids, complete protein or incomplete/complementary protein in sufficient quantity must be eaten every day.
How much is enough to be considered sufficient? As a general rule of thumb, 1/3 gram per pound of body weight. If on a resistance training regimen to build muscle or retain muscle while shredding fat, your requirement may be higher – as high as 1 gram per pound of body weight.
Protein is the macronutrient we can absolutely not live without. Be sure to get your recommended daily allowance of essential amino acid each and every day as our body does not store it and must make it. Without the raw material to work with, it can’t do its job and our health will suffer as a result.
Protein vs. Carbs for Post-Workout Snacking: Which is Best?
After a workout, especially weight or resistance training, muscles are significantly lowered of glycogen. Workouts anywhere from 6 to 20 sets done over a period of 15 to 30 minutes will reduce glycogen by 30 to 40 percent. Workout lasting longer, or including high intensity training, deplete glycogen stores even farther – down 60 to 75%!
To take advantage of maximum recovery and muscle rebuilding, it is important to replenish glycogen within two hours of ending a workout by consuming fast-digesting carbs. This enables the glucose from the carbs to enter the bloodstream almost as quickly as ingested. By replacing the glycogen in the muscles, water is pulled in maximizing muscle size. Why is this important?
Muscle cell volume is required for long-term muscle growth (as is protein, but more on that later). So by getting glucose into the muscles fast, it pulls in water increasing muscle size leading to building muscle mass. Muscle growth starts with getting glucose back into the muscles fast.
Studies have shown that by delaying replenishment over two hours reduces glycogen replenishment by as much as 50%. Yes, the body will eventually replenish glycogen over the course of 24 hours, but at the expense of building muscle mass as quickly.
The best fast-digesting carbs is pure dextrose. Some candies are mostly dextrose such as gummy bears or pixie sticks. Some bodybuilders eat fruit immediately after a workout, but the natural sugar in fruit is fructose, which is a much slower digesting-type of sugar, so it must first travel to the liver where it is turned into glucose, sent to the bloodstream and then onto the cells. Much of this happens outside the two-hour window.
When we workout, muscle tissue is damaged at the cellular level. The damaged protein must be broken down and eliminated and new protein created, called protein breakdown and protein synthesis respectively; together the process is called protein turnover. Don’t confuse this protein process with the macro-nutrient protein that we get from food.
This is where eating protein post-workout comes in. It aids in protein synthesis which helps develop muscle mass. It can take as little as 20 grams of protein to stimulate protein synthesis.
So to answer the question which is better post-workout? Alone, neither. You need both post-workout glucose from carbs and protein in the cells of the muscle to gain muscle mass. One without the other is ineffective.