Do Runners Need Dairy to Lose Weight?

There are some staples that are known as runner foods. These foods can be relied upon to keep injuries at bay, and are safe choices for the days leading up to a big race.

A high dairy intake was always in this category, and although most of us would not want to consume dairy a few hours before a race, it is pretty common to see runners enjoying dairy in daily life. After all, you want to keep those bones strong to prevent fractures. Dairy products are also great sources of protein and carbohydrates, and studies have even found that chocolate milk is one of the best recovery choices a runner can make.
Oh, and of course we don’t have to mention that they taste good!

However, in recent years, dairy has been attacked, and many runners no longer consume dairy products at all. This is not surprising when you look at just how many harmful or unhealthy dairy products there are out there, especially those products high in added sugars, preservatives and hormones, like flavored yogurt and cheese sticks.

Not too long ago, the world was on a no-fat diet. Non-fat (skim) milk was brought in to allow us to get the protein and carbohydrates, without making us gain weight. But in recent years, we have discovered that fat itself is not necessarily what is causing us to gain weight, it’s the added sugars and the pure volume we eat.

If you are looking to lose or maintain weight, keeping dairy in your diet is not necessarily a bad thing, and actually should be something you continue to consume (unless, of course, your body is intolerant to dairy). But, it’s important to think smart when choosing the type of dairy.

Does dairy help runners lose weight?
Most people who want to lose weight would ideally only lose fat tissue. But, when you lose weight in an unhealthy way (i.e. extreme calorie restricting instead of strength training), you will also lose some lean (muscle) tissue. This is why most people using a weight-loss program eventually gain the weight back again, even if caloric intake has not increased. Your muscles are metabolically active, which means they continue to burn calories, and keep your metabolism high even when you are not exercising.
In 2011, Josse et al. looked at how dairy consumption affected weight loss and fat loss in obese and overweight women following a calorie-restricted diet combined with daily exercise. They found that consuming a high-dairy, high-protein diet resulted in more fat loss, without losing the lean muscle.

One reason to consider organic whole milk over non-fat milk is the increase in fecal fat excretion as the calcium prevents some of the fat from being absorbed in the intestines. The fat content in whole milk is also going to slow digestion, which will help you stay fuller for longer, making it easier to avoid overeating. This goes again with the fact that fat doesn’t make people fat. While we may think that reaching for a low-fat or non-fat variety would be better, it’s actually not. Reduced-fat dairy products often contain other chemical ingredients and added sugar to taste “better.” So, go organic whole milk!

The effect of leucine on weight loss
Some studies compared calcium supplements with the consumption of dairy foods, and found that although both resulted in fat loss when combined with a caloric-restricted diet, there was more weight loss for the participants consuming dairy products than those taking a supplement. This led the researchers to believe that there must be something beyond the calcium that results in the weight loss. Leucine is thought to be responsible.

Leucine cannot be produced by the body, as it is one of the 9 essential amino acids that must be consumed through diet. It is also a three branched-chain amino acid, which has been used by athletes to prevent fatigue, improve performance and limit muscle breakdown. It is most often found as a supplement, but can also be found in high-protein products, particularly those containing whey protein, which is found in dairy products. Leucine is the only amino acid that stimulates protein synthesis in the muscle, which leads to a growth in lean muscle tissue when combined with strength training or hard running workouts.

Even runners who are not trying to lose weight, like those following a marathon training schedule, will benefit from consuming leucine in their diet, as it helps the body to maintain steady glucose levels during endurance running. During long runs, consuming leucine will help to maintain blood sugar levels, and allow your muscle glycogen to be saved for later, which will help to prevent bonking in a race.

Finally, leucine can help the body to convert alanine into glucose for energy, which prevents your body breaking down your lean muscle protein to make glucose for energy. For these reasons, keeping leucine as a regular part of your diet, especially when in an intense training period, can allow your body to cope better, and handle the longer training sessions.

What about dairy consumption after exercise?
Leucine can help us during marathon training, but does it help runners after a hard workout?

Yes!

Research has found that drinks containing protein and carbohydrates are better at rehydrating and refueling than products only containing carbohydrates. Products containing whey protein are better at stimulating muscle synthesis after exercise because the body can digest it much quicker than other protein sources. Whey protein has a much higher concentration of leucine, making it very effective at stimulating muscle protein synthesis.

Another study comparing muscle protein synthesis of whey protein and soy protein found that whey protein resulted in 18% higher protein synthesis at rest and 31% after resistance training than soy.

How much leucine is needed for recovery?
Research shows that 2.5 g of leucine after exercise is enough to stimulate muscle protein synthesis, limit soreness in the muscles and improve recovery. Dairy products and protein powders are the best sources of whey protein, and therefore leucine.

What about lactose intolerance?
Some runners will be unable to consume the milk products because of dairy intolerance (or other ethical or personal reasons), which will mean they need to consume calcium, vitamin D, and ideally, leucine, from other sources. Foods high in leucine include soybeans, fish, nuts and seeds. Other runners will have to consider timing the consumption of dairy to prevent an upset stomach during a run.

When it comes to consuming dairy products, try out different sources and consumption levels to see how your stomach handles them. It is important to find what works for you, and try to stick with that moving forward

We have covered a few of the reasons you should consider keeping dairy in your diet, despite the bad reputation it has gained over the past few years.

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