Exercise and Weight Loss

Written by Dr. Steve Chaney on . Posted in current health articles, Exercise, Healthy Lifestyle, Lose Weight

Author: Dr. Stephen Chaney

exercise and weight lossAre you confused yet?  Just as you were starting to wrap your mind around the current consensus recommendations that we engage in 30 minutes of moderate intensity exercise 5 days/week, news stories are starting to appear saying that might not be enough exercise if you want to lose weight!

So how much exercise DO you need, and why is there so much confusion with exercise and weight loss?

Let me start by reviewing a couple of studies that appeared a few years ago on weight loss in middle aged, overweight women.

 

Exercise and Fat Loss

The first study looked at the effect of exercise intensity on abdominal fat loss over a 16-week period(Irving et al, Medicine & Science In Sports & Exercise,40: 1863-1872, 2008).

The women in this study were divided into three groups:the control group that just continued their normal exercise pattern (little or none), a group that engaged in supervised moderate intensity exercise 5 days per week, and a group that engaged in supervised, high intensity exercise 3 days per week and moderate intensity exercise the other two days.

The diet was identical for all three groups and the calories expended by exercise were also identical (the high intensity exercise was performed for shorter periods of time so that the calories expended were the same).

The results were striking. Weight loss was similar in the two exercise groups (calories do count). However, the women in the high intensity exercise group lost a significant amount of abdominal fat while the other two groups did not! As you may know, abdominal fat appears to be much more damaging metabolically than fat stores in other parts of our bodies.

 

Exercise and Weight Loss

woman runningThe second study looked at the effect of exercise duration on weight loss over a 24-month period (Jackcicet al, Archives of Internal Medicine, 168: 1550-1559,2008).

In this case the diet and the intensity of the exercise(moderate intensity) were the same. The difference was in the duration of the exercise. In this case the calories expended by exercise was not kept the same. The group that exercised for longer burned significantly more calories than those who exercise for a shorter time.

Again the results were striking. Only those study participants who exercised for at least 275 minutes/week (an average of almost 60 minutes a day for 5 days) were able to lose 10% or more of their weight and keep the weight off over a 24-month period.

 

How Much Exercise is Enough?

So what does all of this mean to you?

how much exercise is enoughWhen most Americans decide to shed a few pounds, one of the first things they think of is getting more exercise. After all, it’s much easier to walk around the block during lunch hour than to actually change what you are eating.

The question then becomes how much exercise is enough? Is the recommended 30 minutes a day of moderate intensity exercise 5 days per week enough?

If you actually work through the math, it is pretty easy to guess that it might not be enough. For example, a recent study looked at how much moderate intensity exercise would be required for a 155-pound woman to burn off the calories in same popular fast foods. For example, to burn off the calories:

  • In a MacDonald’s Big Mac, she would need to cycle at a moderate pace for 1 hour.
  • In an Arby’s Reuben, she would need to walk at a moderate pace for 3 hours.
  • In a Super Sonic Double Cheeseburger with Mayo, she would need to do low impact aerobics for 3 hours.

Of course, if she had fries and a soda with any of those meals she would need to do even more exercise.

weight loss and dietThese estimates are not just hypothetical. The studies described above clearly show that if you are relying on exercise alone to shed your excess pounds and/or excess fat, you are going to need higher intensity exercise and/or longer duration moderate intensity exercise than the current consensus recommendations suggest.

In other words, the current recommendations of 30 minutes of moderate intensity exercise 5 days per week probably won’t make much of a dent in your weight unless the exercise is coupled with a very good weight loss program.

But, if you have ever relied on exercise alone for weight loss, you have probably guessed that already!

Of course, the consensus recommendations are still valid for what they were designed to accomplish. 30 minutes a day of moderate intensity exercise 5 days per week is sufficient to improve fitness and reduce cardiovascular risk factors.  And fitness reduces your risk of disease even if you are still overweight.

Furthermore, since many Americans probably don’t get even 30 minutes of exercise in a week, 30 minutes 5 days per week is a great starting goal.

 

The Bottom Line 

Recent studies show that the current recommendations of 30 minutes of moderate intensity exercise 5 days per week probably won’t make much of a dent in your weight unless the exercise is coupled with a very good weight loss program.

Don’t freak out about all of the conflicting exercise recommendations. Here’s what I suggest:

1) Consult with your physician before you start any exercise program.

2) Get active. Start slowly and start by choosing activities that are fun and accessible to you.

3) Set your goal of 30 minutes of moderate intensity exercise 5 days per week. If you want to lose weight, couple that with a well-designed weight loss program.

4) If your combination of exercise and diet isn’t putting a dent in your weight and weight loss is important to you, pick up the pace or increase the duration of exercise.

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Trackback from your site.

Comments (2)

  • Helen T. Govedarica

    |

    Thank you for your wonderful info laden emails. They help me feel more knowledgeable when talking to my downline.

    Please note I have a new email address and am just making sure that you have changed your records.

    Thank You.

    Reply

    • Dr. Steve Chaney

      |

      Your records have been updated

      Reply

Leave a comment

Recent Videos From Dr. Steve Chaney

READ THE ARTICLE
READ THE ARTICLE

Latest Article

High Protein Diets and Weight Loss

Posted October 16, 2018 by Dr. Steve Chaney

Do High Protein Diets Reduce Fat And Preserve Muscle?

Author: Dr. Stephen Chaney

Healthy Diet food group, proteins, include meat (chicken or turkAre high protein diets your secret to healthy weight loss? There are lots of diets out there – high fat, low fat, Paleolithic, blood type, exotic juices, magic pills and potions. But recently, high protein diets are getting a lot of press. The word is that they preserve muscle mass and preferentially decrease fat mass.

If high protein diets actually did that, it would be huge because:

  • It’s the fat – not the pounds – that causes most of the health problems.
  • Muscle burns more calories than fat, so preserving muscle mass helps keep your metabolic rate high without dangerous herbs or stimulants – and keeping your metabolic rate high helps prevent both the plateau and yo-yo (weight regain) characteristic of so many diets.
  • When you lose fat and retain muscle you are reshaping your body – and that’s why most people are dieting to begin with.

So let’s look more carefully at the recent study that has been generating all the headlines (Pasiakos et al, The FASEB Journal, 27: 3837-3847, 2013).

The Study Design:

This was a randomized control study with 39 young (21), healthy and fit men and women who were only borderline overweight (BMI = 25). These volunteers were put on a 21 day weight loss program in which calories were reduced by 30% and exercise was increased by 10%. They were divided into 3 groups:

  • One group was assigned a diet containing the RDA for protein (about 14% of calories in this study design).
  • The second group’s diet contained 2X the RDA for protein (28% of calories)
  • The third group’s diet contained 3X the RDA for protein (42% of calories)

In the RDA protein group carbohydrate was 56% of calories, and fat was 30% of calories. In the other two groups the carbohydrate and fat content of the diets was decreased proportionally.

Feet_On_ScaleWhat Did The Study Show?

  • Weight loss (7 pounds in 21 days) was the same on all 3 diets.
  • The high protein (28% and 42%) diets caused almost 2X more fat loss (5 pounds versus 2.8 pounds) than the diet supplying the RDA amount of protein.
  • The high protein (28% and 42%) diets caused 2X less muscle loss (2.1 pounds versus 4.2 pounds) than the diet supplying the RDA amount of protein.
  • In case you didn’t notice, there was no difference in overall results between the 28% (2X the RDA) and 42% (3X the RDA) diets.

Pros And Cons Of The Study:

  • The con is fairly obvious. The participants in this study were all young, healthy and were not seriously overweight. If this were the only study of this type one might seriously question whether the results were applicable to middle aged, overweight coach potatoes. However, there have been several other studies with older, more overweight volunteers that have come to the same conclusion – namely that high protein diets preserve muscle mass and enhance fat loss.
  • The value of this study is that it defines for the first time the upper limit for how much protein is required to preserve muscle mass in a weight loss regimen. 28% of calories is sufficient, and there appear to be no benefit from increasing protein further. I would add the caveat that there are studies suggesting that protein requirements for preserving muscle mass may be greater in adults 50 and older.

The Bottom Line:

1)    Forget the high fat diets, low fat diets, pills and potions. High protein diets (~2X the RDA or 28% of calories) do appear to be the safest, most effective way to preserve muscle mass and enhance fat loss in a weight loss regimen.

2)     That’s not a lot of protein, by the way. The average American consumes almost 2X the RDA for protein on a daily basis. However, it is significantly more protein than the average American consumes when they are trying to lose weight. Salads and carrot sticks are great diet foods, but they don’t contain much protein.

3)     Higher protein intake does not appear to offer any additional benefit – at least in young adults.

4)     Not all high protein diets are created equal. What some people call high protein diets are laden with saturated fats or devoid of carbohydrate. The diet in this study, which is what I recommend, had 43% healthy carbohydrates and 30% healthy fats.

5)    These diets were designed to give 7 pounds of weight loss in 21 days – which is what the experts recommend. There are diets out there promising faster weight loss but they severely restrict calories and/or rely heavily on stimulants, they do not preserve muscle mass, and they often are not safe. In addition they are usually temporary.  I do not recommend them.

6)    This level of protein intake is safe for almost everyone. The major exception would be people with kidney disease, who should always check with their doctor before increasing protein intake. The only other caveat is that protein metabolism creates a lot of nitrogenous waste, so you should drink plenty of water to flush that waste out of your system. But, water is always a good idea.

7)     The high protein diets minimized, but did not completely prevent, muscle loss. Other studies suggest that adding the amino acid leucine to a high protein diet can give 100% retention of muscle mass in a weight loss regimen – but that’s another story for another day.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

UA-43257393-1