Dairy and Weight Loss
Saturday, September 29, 2012
LifeTime WeightLoss in Nutrition, Tom Nikkola, calorie balance, dairy, weight loss

Two weeks ago, we looked at the effects of high-fat dairy as it relates to heart health. Overall, full-fat dairy has been shown to have somewhere between a beneficial and neutral effect on the risk of developing heart disease, stroke and other related issues. The idea that dairy fat can be a contributor to heart disease appears to be without merit. Of course, there are other concerns people have related to full-fat dairy, such as its effect on weight management, the types of dairy individuals should consume and, of course, there’s the question of whether or not some people should even consume dairy at all. We’ll continue the dairy consumption discussion today by focusing on the impact full-fat and non-fat dairy have on weight management, as well as look at the nutrient values of conventional, organic and grass-fed dairy.

Dairy and Weight Management

Many studies and papers have been written about the importance of dairy in a weight management plan. Some of the papers focus on the importance of calcium in the regulation of fat metabolism. Others focus on the protein benefits. Unfortunately, most of the weight management-related dairy studies have either been observational studies, where consumers were asked about their dairy consumption in general, not specifying low-fat versus high-fat dairy, or the studies have been controlled studies that used low-fat dairy to replace other foods in the diet. There is a lack of good research comparing higher levels of low-fat and higher levels of full-fat dairy on weight management. However, it is well known that a low-fat approach to weight management is usually unsuccessful in the long term. It is also well known that the fat found in dairy contains important nutrients which may help the body regulate body fat levels.

In order to make assumptions about dairy’s effect on body fat levels, this issue can be looked at a couple different ways:

To answer the first question, you must understand how diet studies can be constructed. For example, if a study is designed in a way where dairy products are consumed three times per day in place of bread, juice or pastries, you can almost be assured that dairy will come out favorably. Unfortunately, all that you know at the end of the study is that dairy is better than the foods that the dairy replaced. That does not mean that dairy is the best solution for weight management, only that it is a better choice. Would fish, meat or poultry be even better yet, being that they have no sugar and are higher in protein by percentage? Would these options also be better because a fair number of people have trouble with lactose or casein in milk?

For example, a 2005 study compared the consumption of a commercial yogurt three times per day as part of a calorie-reduced diet against a standard diet that was more restricted in dairy products. The yogurt group showed better losses of body fat, including belly fat and less lean body mass loss, along with a few other improved health markers. However, it’s difficult to determine whether the loss was from the fact that dairy provides a high-quality protein source, or was it that the yogurt group took in twice as much calcium as the other group, or could it even be that the yogurt provided live bacterial cultures which could be beneficial for gut health, which has also been shown to be beneficial for body fat regulation. The downside of this particular study was that the yogurt used also included the artificial sweeteners aspartame and acesulfame potassium (Ace-K) and artificial colors.[i]

Other similar studies have produced similar results. Many of the recent studies on dairy used low-fat or non-fat dairy to compare against groups who consumed little to no dairy. In some of the studies, the result was a higher overall protein intake, which could be a big reason for the increased fat loss and better maintenance of lean body mass.[ii]

I wasn’t able to locate weight loss studies using full-fat dairy, or studies comparing fat loss results of full-fat dairy to low-fat dairy and conventional diets. Possibly, researchers or those funding the research have a bias that they bring to the study design, assuming low-fat and non-fat dairy will be more effective. This is unfortunate, as the fat found in dairy provides a variety of important nutrients. Without clinical studies to show the effects, we must look at what the nutrients found in dairy fat provide, and understand what we’re missing out on by not consuming them.

Dairy Fat

CLA

Conjugated Linoleic Acid (CLA) is one of the most significant nutrients related to dairy fat’s effect on body fat regulation. CLA is formed when microbes in cattle convert linoleic acid in their food into CLA. When cattle are fed their natural diet of grass, they produce more CLA than when they’re fed grain, as most are in a feedlot or conventional dairy farm.

Not all CLA is the same, and some is made synthetically. Naturally occurring CLA in dairy is typically found in two forms; cis-9, trans-11 which makes up 90% of the CLA and trans-10, cis-12 which makes up 10%. While the chemical structure is not important for this article, it is important to know there are other forms that can be made in a lab and used in supplements., But it’s the cis-9, trans-11 / trans-10, cis-12 combination that is the naturally occurring form, and the one that’s been shown to have associated health benefits. Research has shown these two forms of CLA support fat loss and lean mass gain.

As a side note, it’s this type of CLA, under the brand name Clarinol® that we use in LeanSource, our weight loss support supplement. Clarinol, which combines the 9,11 and 10,12 forms of CLA, has solid scientific research to support its use in body fat regulation. Other brands of CLA have not produced consistent results as they may include other forms of CLA.

CLA’s effect on body composition appears to come through a variety of mechanisms. It’s been shown to reduce energy intake and increase energy expenditure through elevated basal metabolic rate, suppression of fat storage, and increased lipolysis, or fatty acid breakdown.[iii]

Saturated Fats

Dairy fat contains a variety of saturated fats which have proven health benefits as well. Butyric acid modulates gene function and may help in cancer prevention, caprylic acid may slow tumor growth,[iv] and lauric acid has been shown to have antiviral and antibacterial properties, even being able to kill H. pylori.[v] These healthy fats provide good reason to use butter for cooking rather than many of the highly processed vegetable oils or other man-made fats on the market.

Unsaturated Fats

Oleic acid is found in dairy fat, as are the polyunsaturated fatty acids (PUFAs) linoleic and alpha-linoleic acid. Though the human body is not great at converting ALA to the health-promoting essential fatty acids EPA and DHA commonly found in fatty fish, ALA can provide a non-fish source of some of these important nutrients. Part of the issue with the fats we consume today is that our ratio of omega-6 to omega-3 fatty acids is so high. Dairy fat has a very low ratio of omega-6 to omega-3 fats compared to many other non-marine products.[vi]

Protein

Depending on the type of dairy one consumes, it can be seen as a good source of protein. Butter and heavy cream have many of the rich fatty acids mentioned above, but lack protein. Cheese, on the other hand, has very little carbohydrate and, by percentage, a greater amount of fat and protein. Most of the protein in dairy comes from casein. In milk, casein makes up about 80% of the total protein amount, with whey making up the remaining 20%. Unfortunately, a fairly significant percentage of people have trouble digesting casein which presents a problem with consuming milk, along with those who have lactose intolerance. This is a topic we’ll cover at another time.

Casein digests slowly, so amino acids are released at a steadier rate. Whey protein is digested rapidly, which is why it is such a popular supplement for use before, during or after exercise. Of the two proteins, when used by themselves, whey protein appears to be one of the best sources of dietary protein available. Well before research was available, an Italian proverb dating back to about 1777 declared “If everyone was raised on whey, doctors would be bankrupt.”[vii]

Other proteins found in milk that have health benefits include immunoglobulin A, lactoferrin and lactalbumin.

Amino acids are building blocks of protein and play important roles in body functions, especially in the maintenance of lean body mass, which is important for improving overall body composition. Dairy is rich in essential amino acids, which the body cannot make on its own. Of the essential amino acids, three of them — leucine, isoleucine and valine — play important roles in muscle protein synthesis.

From a body composition standpoint, it’s likely that the lower body fat levels seen in those who consume higher amounts of dairy come at least partly from a higher intake of high-quality protein.

Dairy is also a good source of the minerals calcium, selenium, magnesium and others. Beyond the protein in dairy, it’s very possible these micronutrients play a role in the weight management benefits of dairy.

Dairy and Weight Loss

The point of this second post on dairy was to address possible body composition benefits. Does consuming larger amounts of dairy offer body composition benefits? According to research, it appears so. In fact, the available research suggests that full-fat dairy may be better than low-fat or non-fat dairy for body fat regulation, because the fat in dairy has some powerful metabolism-regulating components in it. While some people attempt to eat fewer calories by choosing low-fat or non-fat food, research does not support this. Often, people end up eating more of other foods and make up the calories they thought they were avoiding because fat is a great appetite suppressant.

All this said, it doesn’t mean dairy should be added to what one is already eating. Instead, it should take the place of something else. It also doesn’t mean dairy is appropriate for everyone. And even for those who can consume dairy, there are good reasons why it probably shouldn’t be consumed every day.

Using the term “dairy” as I have throughout this and the previous blog posts makes it sound like all dairy is the same. That is not the case. Dairy foods include cheese, milk, cream and butter. Some would include ice cream in the list, but when looking for weight loss, a sugar-laden dessert, even if it contains some good nutrients from dairy, is unlikely to support one’s weight loss goals.

Cheese, milk, cream and butter can be used in the context of a healthy diet, but they do require some additional clarification. Beyond the type of dairy, the source makes a difference as well. There is a difference in what you put in your body when you buy conventional dairy, organic dairy or grass-fed dairy. That's what we'll talk about next week.

Lastly, even with the best-quality dairy products, not everyone should consume them. Allergies and intolerances can play a role in health as well as the ability to properly manage weight. We’ll cover these topics in upcoming blog posts.

Have you been successful in using dairy for weight loss? If so, share your experience below. Or just post comments or questions you have on the topic.

Written By Tom Nikkola - Director of Nutrition and Weight Management


[i] Zemel MB, Richards J, Mathis S, et al. Dairy augmentation of total and central fat loss in obese subjects. Int J Ob. 2005;29:391-397

[ii] Josse AR, Atkinson SA, Tarnopolsky MA, Phillips SM. Increased Consumption of Dairy Foods and Protein during Diet- and Exercise-Induced Weight Loss Promotes Fat Mass Loss and Lean Mass Gain in Overweight and Obese Premenopausal Women. J Nutr. 2011;141:1626-1634

[iii] Kennedy A, Martinez K, Schmidt S, et al. Antiobesity Mechanisms of Action of Conjugated Linoleic Acid. J Nutr Biochem. 2010;21(3):171-197

[iv] Thormar H, Isaacs EE, Kim KS, Brown HR. Interaction of visna virus and other enveloped viruses by free fatty acids and monoglycerides. Ann N Y Acad Sci 1994;724:465-471

[v] Sun CQ, O’Connor CJ, Robertson AM. Antibacterial actions of fatty acids and monoglycerides against Helicobacter pylori. FEMS Immunol Med Microbiol. 2003;36:9-17

[vi] Haug A, Hostmark AT, Harstad OM. Bovine milk in human nutrition – a review. Lipids in Health and Disease. 2007;6:25 http://www.lipidworld.com/content/6/1/25

[vii] Johnny Bowden. The 150 Healthiest Foods on Earth. p. 243. 2007. Fair Winds Press. Beverly, MA.

This article is not intended for the treatment or prevention of disease, nor as a substitute for medical treatment, nor as an alternative to medical advice. Use of recommendations in this and other articles is at the choice and risk of the reader.

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