Learn how adding skim milk to your diet can help you build muscle, strengthen bones and maybe even lose some body fat along the way.
Milk it does a body good has a new meaning for people looking to add muscle, stave-off bone loss and reduce body fat.
A flurry of research albeit, mostly funded by the dairy industry over the past few years has suggested that including skim milk or fat-free milk into your diet can actually help you lose weight. But aside from the weight loss claims (which well take a look at later), there are additional reasons that including skim milk in your diet can keep you fit, trim and healthy.
What is Skim Milk?
Skim milk is whole milk from dairy cows that has most or all of its fat removed.
Traditionally, this was done by letting milk settle, and then skimming the fat off the top of the milk. What is left is the protein-rich, low-fat liquid below the layer of fat. In modern milk processing, the de-fatting process is done with centrifuges (basically the milk is spun around inside a big stainless steel tank and the fat is separated and drained off.)
Skim milk (also labeled as fat-free milk or non-fat milk) generally has less than 0.5 percent milk fat. Low-fat, semi-skimmed milk or 1% milk has between 1 and 2 percent fat. For comparisons sake, whole cows milk has around 3.5 percent fat, or 7.9 grams of fat (4.6 grams of which are the bad saturated type of fat) in a 1 cup (16 oz) serving. In terms of calories, whole milk weighs in at 147 calories, in comparison to the 91 calories in skim milk.
Clearly choosing skim milk over whole or even 2% milk makes the most sense from a fat and calorie perspective.
But what about the difference in nutrition between skim milk and whole milk? Does the skimming process remove any nutrients?
Nutritional Content of Skim Milk versus Whole Milk
Ironically, while processing normally strips out nutrients in other foods like whole grains, in the case of skim milk, the skim or fat-free varieties of milk are actually more nutritionally-dense than the whole or full-fat versions.
How could this be? After all, youre removing something from the whole milk, right? Doesnt that usually mean you lose something?
You do. You lose the stuff you dont want namely the artery-clogging fat and you end up with more of the good stuff (protein) gram-for-gram than with the whole milk. This is because when you remove the fat, you increase the amount of protein available in the same amount of liquid. And the protein is the stuff that really makes skim milk shine.
Lets compare the protein, carbohydrate, calcium and potassium levels of a 8 oz serving of whole milk versus the same serving size of skim milk.
An 8 oz serving of whole milk contains:
- Protein: 7.9 g
- Carbs: 11 g
- Calcium: 276.1 mg
- Potassium: 349 mg
- Cholesterol: 24 mg
- Sodium: 98 mg
Versus the same volume of skim milk:
- Protein: 8.7 g
- Carbohydrates: 12.3 g
- Calcium: 349 mg
- Potassium: 419 mg
- Cholesterol: 5 mg
- Sodium: 130 mg
So contrary to what many people think, whole milk does not have more protein than skim milk.
Carbohydrates are slightly higher in skim milk versus whole milk, and so are sodium or salt levels, but this is a function of removing the fat from skim milk, which leaves behind a slightly higher ratio of sodium and carboydrates by volume. Manufacturers do not add salt to skim milk. The skim milk is also significantly higher in potassium and calcium. In terms of cholesterol and skim milk, skim has much less cholesterol than whole milk.
Skim Milk Vitamin Content
In terms of vitamins and minerals, whole milk does naturally contain fat-soluble Vitamins A, D, E and K, but these vitamins are concentrated in the fat within the milk. Since skim milk has had the fat removed, manufacturers fortify skim milk with Vitamins A and D in order to restore the natural-vitamin profile of the milk. So in this regard, the Vitamin profile of whole milk is more natural than skim. However, from a total vitamin perspective, the fortification process makes the two more or less equal on this front (without the added calories and fat of whole milk.)
Milk also contains a fair amount of riboflavin, also known as Vitamin B2, in the whey portion of milk which after production can impart a slightly greenish hue or tint to skim milk. Skim milk also contains trace amounts of iodine, Vitamin B12, biotin and pantothenic acid, thiamine, selenium and magnesium.
So given the choice (based on the lower fat and calories,) the healthier option is typically to go with the skim.
What Are Those Other Ingredients in Skim Milk?
The ingredient list on a carton of skim milk should be pretty short: fat free milk and maybe a few other fancy sounding ingredients like Vitamin A Palmitate and Vitamin D3. Any additional ingredients are typically synthetic vitamins added to increase the nutritional profile of skim milk. Notice that water is not listed in the ingredients.
Skim Milk: Casein Protein Powerhouse
One of the primary health and nutritional advantages to skim milk is that its a good source of protein, specifically slow-digesting casein protein. Skim milk contains dozens of proteins, including casein and whey proteins (which make up around 20 percent of the protein in skim milk by weight.) Lactoglobulin is the most predominate whey protein in milk and skim milk products.
Casein protein, specifically casein protein micelles, are an interesting contrast to whey protein, especially for bodybuilders and people pursuing a resistance or weight training regimen. Unlike whey protein, which is digested very quickly by the body (in some cases in under 30 minutes), casein proteins in skim milk can take much longer for the body to break down and digest (some estimates say as long as 7-8 hours for casein to be fully-digested.)
While this might sound like a bad thing, it can actually be beneficial, especially if your goal is to make sure that your body has a constant supply of protein available post-workout for muscle recovery and growth.
Because casein has a longer digestion window than whey, skim milk is an excellent source of slow-digesting protein, especially before you go to bed. The slow digestion of casein proteins in skim milk will ensure that you remain in positive nitrogen balance (meaning you have sufficient protein available to the body) during the nighttime fast.
DID YOU KNOW? Contrary to popular belief, skim milk is not watered-down whole milk. Its simply whole milk without the fat. This, of course, changes the texture, mouth-feel and flavor of the whole milk, making skim feel a bit thinner and less creamy than whole milk (its the fat that gives it that creaminess and texture.) Manufacturers do not add water to skim milk. If they did, not only would it have to be listed on the ingredients, but it would also make skim milk lower in protein and carbohydrates than whole milk. So while skim milk may taste watered down if you are used to drinking whole milk or even 2% milk, its not.
Got Milk for Muscle? Muscle Building Benefits of Milk
In recent years, there has been a fair amount of research around whether the consumption of milk (typically as part of a post-workout recovery drink) can encourage greater gains in lean muscle versus other recovery drinks like carbohydrate drinks, whey protein or soy protein.
An April 2007 research article published in the American Journal of Clinical Nutrition found that milk-based proteins (skim milk was actually used in this study) promoted greater muscle protein uptake than soy-based proteins when consumed after resistance exercise. The researchers concluded that while both soy milk and skim milk resulted in a positive net nitrogen balance, those who regularly consume milk proteins after resistance training would likely experience greater lean mass gains (greater muscle.)
A 2007 Canadian Study led by Stuart Phillips at McMaster University (and funded in-part by the Dairy Council) and also published in the American Journal of Clinical Nutrition, involved 56 men aged 18 to 30 who signed up for a rigorous five-day-a-week weightlifting program over a 12-week period. One group was given about two cups of skim milk post-workout (approximately 17 grams of protein and 25 grams of carbs), another was given a soy drink with identical ratios and a third was given a carbohydrate-only sports drink. The study was blind (and identical flavors were used) to blunt any placebo effect.
By the end of the study, all three groups had gained lean muscle and most lost fat, but the milk drinkers lost the most fat (on average two pounds of fat each, compared with one pound for the sports drink and no pounds for the soy group.) The milk drinkers also came out ahead in the muscle department, gaining 2.5 pounds more of lean tissue than the soy group and 3.3 pounds more than the carbohydrate-sipping sports drink group.
Finally, another study, led by Darren Willoughby at Baylor University, suggests that the combining skim milk, whey protein and a carbohydrate post-workout is more effective at building lean mass and anabolic markers than consuming carbohydrates alone.
Milk and Weight Loss?
But what about all of the buzz around milk as a weight-loss and fat burning aid?
The milk for weight loss craze started with the publication of a research study led by Michael B. Zemel of the University of Tennessee (Knoxville) and published in the April 2004 issue of Obesity Research. The research article, Calcium and Dairy Acceleration of Weight and Fat Loss During Energy Restriction in Obese Adults, found that obese people who ate 2-3 servings of milk or dairy products on a reduced-calorie diet lost an average of 24 lbs in six weeks significantly more weight than the group who consumed the same amount of calories but little or no milk, according to the researchers.
Prior to the Obesity Research article, there had been some telltale research that indicated that dairy (or perhaps more specifically, increased calcium intake) might help people shed weight, or at least maintain their weight levels. A 2000 study on the effect of calcium intake on body weight among women by Creighton University researcher Dr. Robert Heaney found that women with higher calcium intake (not necessarily via milk products) tended to weigh less. His data also indicated that each 300 mg increase in calcium lowered average body weight by about six pounds.
There are dozens of additional research studies, many of them funded by The National Dairy Council or other dairy industry groups, that link higher milk or calcium intake with weight loss. In fact, its estimated that the dairy industry has spent over $200 million since 2003 promoting the idea of dairy as a weight loss aid. Most of the studies are published in peer-reviewed journals, so while the research may have been funded in part by a group representing the dairy industry, the methodology and results are available for review and attempted replication.
Not all research on the connection between dairy, calcium and weight loss is so positive. A 2006 study by Purdue University tracked 155 women between the ages of 18 and 30 for one year and found that none of the women lost or gained weight, regardless of their calcium intake (in the form of dairy products.)
So what should you do?
As always, there are no weight-loss silver bullets. Losing body fat and keeping it off requires a holistic approach to diet, exercise and wellness. However, even if skim milk doesnt turn out to be the fat burning superstar touted in the latest round of Got Milk ads featuring lean and trim celebrities and supermodels, it still can be an important part of your overall fitness diet.
You should also be aware of some of the ideological battles that taint nearly any discussion of milk and its health benefits. As this article (and subsequent discussion in the comments) from the LA Times Booster Shots blog illustrates, this is an emotionally-charge subject for some people, with pro-milk advocates often squaring off against the dairy-is-bad crusaders in endless pissing matches over whether humans were ever intended to even drink cows milk. As in any war, the first casualty is often the truth, and it can be hard to separate out the fact from fiction in the great milk debate. Youll have to read the research on each side yourself, and make your own conclusions.
Did You Know: If the flavor and texture of skim milk leaves you feeling a bit flat compared to whole or 2% milk, you can mix 2% milk with skim milk or fat free milk to get a lighter, tastier version of 2% with slightly less fat and calories. Some stores now are even selling a 1% version or skim plus version of milk that falls somewhere between skim milk and 2%.
What About Milk and Bone Loss?
Skim milk, as we mentioned above is high in calcium, potassium and Vitamin D vitamins and minerals that work together to strengthen bones. Conventional wisdom has said that milk and dairy, being high in calcium, can help stave off osteoporosis.
However, there is conflicting research around how well calcium in dairy products is actually absorbed by the body.
There are also groups (in many Asian countries, for example) that consume very little dairy and as a population exhibit low bone fracture rates and markers of bone loss. Since there is conflicting research around dairy and bone loss, the best approach is to ensure that you are including many different sources of calcium into your diet from a wide-range of foods such as leafy greens, seafood (especially sardines or canned salmon with the bones,) orange juice, nuts, vegetables like broccoli and dairy, if you choose.
Organic Skim Milk Versus Regular
Choosing between organic skim milk and regular skim really comes down to how much you are willing to spend to go organic. Many organic milks are higher in omega-3 fatty acids and Conjugated linoleic acids (CLA), because the dairy cows are free-ranged and fed a diet high in grass, versus grain. However, the defatting process of making skim milk actually may remove many of these healthy fats from the milk.
Organic skim milk also is also typically free of bovine growth hormones and antibiotics. So if youre concerned about these substances (and you probably should be), going organic makes sense. However, many non-organic milk manufacturers are dropping the bovine growth hormones and antibiotics due to public backlash, so even some non-organic skim milk products will be free of them (or at least the manufacturer claims this on the milk carton.) Read the labels carefully to be sure.
In terms of the price of skim milk, organic skim milk will be more expensive. Generally, you should expect to pay between $1 2$ dollars more for organic milk versus non-organic.
Side Effects of Skim Milk
The only proven side-effects of skim milk are around lactose-intolerance. Some people have difficulties digesting the lactose sugars in milk, which can cause stomach upset, gas, bloating or diarrhea.
Luckily, if you are lactose intolerant there are options that allow you still to drink skim milk. There are a number of lactose-free brands of skim milk available on the market, including Lactaid. There are now even organic lactose-free milk product available.
If your grocer doesnt carry lactose-free milk, you can buy tablets that contain the lactase enzyme that you chew before drinking milk which will help your body digest the lactose. There are also lactase drops that can be added to non-lactose free milk to pre-digest the lactose. Many grocery stores and pharmacies will carry these products.
What About Skim Milk Powder?
Skim milk is also available in a powdered form which has a long, stable shelf-life. The powdered form also makes it very convenient to carry along with you when you travel, hike or even into the office.
While skim milk powder has a slightly cooked taste to it once its been rehydrated, when mixed in with other ingredients, like whey protein powder, sauces, or even beverages like tea or coffee, the cooked taste is more-or-less masked by the flavor of the other ingredients.
One other thing: There is a myth floating around the internet that skim milk powder is somehow unhealthy for you because the dehydration process oxidizes cholesterol in the milk, creating carcinogenic nitrates in skim milk powder.
This is simply false.
Because there are no meaningful levels of cholesterol in the skim milk prior to the drying process, there is no cholesterol to oxidize. The cholesterol is removed from the skim milk when its in its liquid state as part of the skimming process, which happens before the milk is dehydrated. Why or how this rumour got started is unclear, but scientifically it has no basis.
Where to Buy Dried Skim Milk Powder
You can usually buy skim milk powder at your local health food store or grocer. If you are looking at buying it in bulk (for instance, if you drink a ton of skim milk or are stocking up on dry goods for the coming apocalypse) you can purchase bulk quantities online (although shipping can be a bit expensive.)
Another little-known source for bulk dry goods including things like non-fat powdered or dry milk is at a local Mormon cannery in your area. They allow the public to come in and buy non-fat dried milk in bulk. They also have facilities for canning the dried milk for storage and will show you how to do it (its very easy.) You can use this online locator to find the closest LDS Cannery to you. Dont worry, they will not try to convert you to Mormonism. They are very nice and helpful and you can buy your dried skim milk at or around wholesale. While youre there you might even consider saving some money on other healthy foods like dried beans, which they also offer at very economical prices.
Uses of Skim Milk
Skim milk is a great, high-protein, low-fat and low-calorie substitute for more sugary beverages like juices and soda.
There is some research that suggests that by substituting low-fat or skim milk for these types of drinks, you can experience weight loss. This really is common sense, since sodas are devoid of nutrition and the high sugar content drives up the calories.
By swapping in lower-calorie beverages like milk, youll lower calories across the day (all things kept equal) and lose weight. So the weight loss may have more to do with eating better foods and less calories than some magical fat-loss property in skim milk. This basically whats at work with my food substitution strategy for staying away from junk food.
Skim milk also makes a good low-fat, lower-calorie substitute for whole milk, cream, or half-and-half in recipes calling for these ingredients, as well as in:
- Creamy Sauces
- Tea (black, green or white)
Of course, you can always drink it straight out of the carton or a glass or pour it over cold, high-fiber, whole grain cereal. You can also richen up hot oatmeal by substituting skim milk for water.
One of my favorite uses of skim milk is in smoothies and protein shakes, where the skim milk helps thicken up the shake, as well as provide a nice shot of casein protein along with the fast-digesting whey powder.
By combining the skim milk with chocolate, vanilla or strawberry whey protein powder and a few ice cubes, you can create a smoothie that better resembles a milk shake. This makes an excellent post-workout recovery drink, especially if you add in some fruit (bananas are my favorite.)
A Few Words on the Great Dairy Controversy
As I mentioned earlier, there is a lively debate over whether human beings should even consume dairy products.
On one side, the dairy-free camp says dairy and milk products are bad for you, causing everything from cancer to allergies to ADHD to low-energy. Some of these critiques are based on solid research, and some of them are based on questionable pseudoscience, personal anecdotes and conjecture.
Dairy free advocates also spend a great deal of time talking about the potential danger (which I happen to agree with) of bovine growth hormones and antibiotics that find their way into milk, as well as the fat content in whole milk and dairy products like cheeses. However, increasingly, its becoming easier to find hormone and antibiotic-free milk products and skim milk takes care of the fat and cholesterol issue.
On the other side, the pro-dairy people point out that low or non-fat dairy is a good low-fat source of protein and is rich in certain vitamins and minerals.
At the end of the day, like so many things when it comes to diet and nutrition, the key is moderation. Consuming 2-3 servings of low or non-fat milk a day should not cause any health issue among most people, and when made part of a well-rounded diet, can help people replace some of their less-healthy calories from things like soda, with a lower-calorie, more nutrient dense food.
So drink up, get a milk-stache and enjoy if you choose.