Fat loss and achieving a lean, strong body is not about starving yourself or spending hours in the gym.
Rather, it is about eating the right foods that energize you, fill you up, and give you the most nutrients per calorie. Protein foods happen to be the best macronutrient for achieving all three of those goals. They are a pivotal component of any diet aimed at changing your body.
Sure, carbohydrates and fat are also important and provide many body composition benefits, but protein deserves special attention for the following reasons:
- It raises your metabolism because it costs the body more calories to process protein than carbs or fat.
- It is filling because eating it causes the release of gut hormones that keep you satisfied.
- It helps manage blood sugar and insulin, decreasing cravings for carbs.
- It triggers protein synthesis, preserving (or building) lean muscle mass so your body burns more calories at rest.
Now, all protein sources are not created equally. Foods differ in regards to their digestibility and nutrient content, which is why the two most important questions you should ask before putting a food in your mouth are:
- Is this food nutrient rich?
- Can my body digest this food easily?
This article will give you the five most nutrient-rich, digestible protein sources and discuss how they can help you get lean. Be aware of two things:
Individual tolerance of protein foods varies based on genetics, so what one person might be able to digest without a negative immune response may not work for someone else.
Physical activity, in particular strength training, is a necessity for health and optimal body composition. You should be training!
Eggs are a perfect source of protein, scoring highest on the scientific scale for protein quality because they provide a wealth of amino acids that are used by the body to repair muscle tissue.
Add to that an array of powerful brain nutrients and beneficial fats and you’ve got a super food that will keep you satisfied and promote optimal body composition.
Just look at all the good things about eggs:
- They have the second highest concentration of leucine after milk, which is the most important amino acid for building muscle.
- They contain choline, which is used by the body to make a critical neurotransmitter called acetylcholine that improves brain function and is beneficial for motivation.
- Choline also helps the liver to detoxify and avoid accumulating fat, and a healthy liver means you’ll have a better metabolism and produce energy efficiently.
- Eggs are high in two important vitamins, D and K, that are fat soluble, which means eggs are a highly bioavailable source that allows for maximal absorption. Both vitamins are necessary for bone building, and vitamin D is involved in metabolic processes and development of muscle quality and strength.
- They are rich in the antioxidants selenium, lutein, and zeaxanthin that can reduce inflammation in the body and promote overall health.
Eggs perform well in weight loss trials and eating them has been found to improve insulin health and metabolism:
- One study found that people who ate 3 eggs a day on a reduced carb diet lost more body fat (5 kg in body in a 12-week study) than a group on a reduced carb diet without eggs.
- Eating eggs for breakfast instead of a bagel results in better glucose tolerance and satisfaction with a meal. Eggs also cause the release of hormones that keep you full, which leads people to eat less at subsequent meals.
- They’re a valuable protein source for athletes. In a review that discusses how egg protein, researchers write that eating eggs can enhance energy production, stimulate protein synthesis, and aid in recovery from intense training.
#2: Whey Protein
You probably know that whey protein is the best “sports” protein because it stimulates protein synthesis more than all other sources, and it has performed well in long-term muscle and strength building studies.
The reason is that along with eggs, whey scores highest in protein quality. Whey is highly digestible and contains boatloads of amino acids that are involved in muscle building, metabolism, and immune function.
What you may not know is that it’s a super fat loss food and it has a number of therapeutic benefits.
Scientists are using it in the clinical setting to cure diabetes, stimulate mitochondrial activity, reduce blood pressure, fix your gut, prevent muscle loss in the elderly, treat cancer, and improve all of the following: antioxidant status, function of the arteries, cholesterol, levels, and bone health.
We won’t go into all the curative applications of whey protein here because it’s completely out of the scope of this article. But here are some of the body composition benefits whey can produce:
- It stimulates fat burning and has a greater thermic effect than other supplemental protein, which means that when you eat it, you burn more calories.
- Taking it regularly can significantly improve blood sugar tolerance and insulin sensitivity, even in diabetics. This is interesting because whey, like all dairy proteins, is very insulinogenic, which means it leads to a release of insulin that is greater than what would be expected.
For example, whey supplementation was found to lead to fat loss in the absence of exercise in overweight men. Insulin levels were lower by the end of the study and the men reported feeling less hungry when taking the whey protein.
- Whey protein can reduce cravings for high-fat, high-carb foods and taking it before eating pizza has been found to lead people to eat significantly less of the pizza. Compared to a control group, a 40-gram dose of whey resulted in subjects eating 100 calories less even when the energy from the whey was added into the calorie total.
- Evidence of the long-term benefit of consuming whey for fat loss is seen with two studies: In one, overweight men took whey protein but didn’t exercise, and lost more fat than a group that took soy protein. In a group of Division III female basketball players, those who took whey in conjunction with training lost more body fat than a group that took soy.
#3: Grass-Fed, Grass-Finished Beef
Beef provides an excellent profile of essential amino acids (it’s packed with the powerhouse branched-chain amino acids isoleucine, leucine, and valine) and it performs well in metabolic studies.
Grass-fed (versus grain-fed or conventional) beef is abundant in non-protein nutrients. It’s high in omega-3 fats that are also found in fish, carnitine (the nutrient that aids in fat for use as fuel), glutamine (known as a muscle builder and immune booster by body builders), glycine and glutathione (immune boosters), and CLA (anti-inflammatory and immune enhancing).
It’s also got zinc (for healthy androgen levels), iron (for energy production), and magnesium (for fighting stress).
All this makes beef useful for body composition:
- Beef builds muscle. Older women who ate 160 grams of lean beef daily in conjunction with a strength training program gained more muscle and increased strength by 18 percent more than a group that ate a carb meal. They also had a16 percent drop in inflammation by the end of the 4-month study.
- Eating beef leads to less hunger by favorably changing hunger hormones, and neural signals that keep you full and satisfied.
- Eating beef regularly when creating a calorie deficit (either by cutting calories or increasing exercise) has been shown to lead to greater fat loss than control diets in which people eat as they normally would.
#4: Salmon & Other Coldwater Fish
You could argue that salmon, sardines, and tuna sans contaminants are the very best fat loss foods because they are so high in omega-3 fats. But wait! This article is about protein content, and fish measures up there as well.
Salmon has 20 grams of protein in one serving of salmon, just slightly less than beef. Salmon has a wide array of amino acids and is higher in the BCAAs than chicken. It’s nutrient rich, providing healthy doses of vitamin B12, niacin, selenium, potassium, and iron.
Fish performs extremely well in dietary intervention studies aimed at reducing body fat and inflammation:
- In young Europeans on a low-calorie diet, those whose main protein source was salmon or cod lost more body fat and reduced oxidative stress markers more than those who just reduced calories.
- A second study showed similar results with the groups that ate fish losing the most body fat. Interestingly, inflammation was reduced most in the salmon group, whereas in the previous study, the cod group lowered oxidative stress markers the most.
- Researchers haven’t pinpointed why cod and salmon are so beneficial for reducing inflammation, but they cite the beneficial fats in seafood. In addition, fish is high in amino acids with antioxidant properties that eradicate oxidative stress, such as taurine and arginine.
What all this means is that variety is paramount when it comes to diet because you’ll get a wider array of nutrients: Don’t just eat salmon or cod everyday. Try mackerel, sardines, shrimp, mussels, scallops, oysters, and whitefishes like tilapia.
#5: Chicken & Poultry
Chicken has the highest protein content per gram, but it’s lower in the powerhouse muscle building BCAAs than the other proteins on this list. For example, in 100 grams of broiled chicken, you get 1.8 g of leucine, whereas in one serving of whey protein you get double that.
But tunnel vision on specific amino acids isn’t all that useful in real life, and the array of amino acids in chicken as well as the different fat sources (mono, poly, and saturated) make it a useful fat loss food.
For example, a study of overweight women on a 1,250 calorie diet for 9 weeks found that those who ate chicken as their primary protein source lost the most body fat (5.6 kg or 3.3 percent) compared to groups that ate beef or carbs.
The chicken group ended up eating the fewer calories daily over the course of the study than the other two groups. The difference in calorie intake between the beef and chicken group was small, but it’s possible that the greater array of amino acids in chicken or a difference in the thermic effect of the proteins influenced body comp changes.
When choosing poultry, most important is the labeling. Marketing has made it impossible for the average person to figure out which foods are safest and most nutritious, but here are a few pointers:
- The term cage-free is irrelevant when it comes to poultry meat because birds raised for eating are not housed in cages even on industrial farms. That’s a practice for egg production. So cage-free means something when it comes to buying eggs, but not meat.
- The label free-range from a large-scale farmer simply means that the animals have access to the outdoors. That doesn’t mean they ever actually go outside. If you can get free-range from a small or local farmer, there’s a better bet the animals made it outside to forage.
- Pasture-raised animals are in fact, raised on the free range, so look for this label rather than free-range.
- The label hormone-free is irrelevant. It's never been legal to give poultry hormones, whereas cows can be raised on hormones.
- Antibiotic-free is a legitimate claim because poultry can be given antibiotics to fatten them up.
- amino acids
- body composition
- body fat
- bone health
- building muscle
- fat loss
- insulin sensitivity
- muscle mass
- optimal body composition
- weight loss
- whey protein