Sunday, November 13, 2022

Do I really have to lift weights if I want to lose weight?

The answer is absolutely yes and for two reasons:

1) To replace age related loss of muscle: We all start to lose muscle as we get older. It is a natural part of the aging process. Muscle is very metabolically active tissue. In other words, it burns lots of calories. A pound of muscle burns three times as many calories as a pound of fat. To keep your metabolism humming, you need to hit the weights at least a few times a week. 

2) To spare lean body mass during the weight loss process: When you lose weight without resistance training, you lose a combination of both muscle and fat. This is one of our body’s defense mechanisms to letting its fat stores get too low, too fast. If 20 or 30% of your weight loss is muscle, your metabolism drops and you’ll burn less calories each day. This makes it much more likely that you’ll regain your lost weight. When you lift weights during the weight loss process, you’ll maintain your muscle mass and metabolic rate, which makes permanent weight loss much more likely.

Mediterranean Diet And Depression

The Study

Seventy-two young males with moderate to severe depression were randomized to either a Mediterranean diet group or a control group for 12 weeks. Here are some of the findings of this interesting study:

-Subjects consuming the Mediterranean diet had a statistically significant reduction in depression scores compared to the control group.

-36% of subjects in the Mediterranean diet group reported low to minimal symptoms of depression by the end of the intervention.

-Subjects in the Mediterranean diet group had significant improvements in quality of life when compared to the control group. These included enhanced concentration, better sleep and improved energy.

American Journal of Clinical Nutrition 2022; 116:572-80.

Take Home Message

The Mediterranean diet has been associated with numerous health benefits for decades in the research literature. This study provides evidence that it may also improve depression.

The authors theorized that the diet’s positive impact on inflammation, oxidative stress and the microbiome could be possible reasons for the association found in this investigation.

It is a great idea to follow a Mediterranean diet. It is also pretty easy to follow:

Carbs: Focus on fruits, vegetables, beans and whole grains.

Fats: Focus on healthy vegetable oils like olive oil and canola oil, nuts, nut butters, seeds and avocados.

Protein: Focus on lean meats like chicken and turkey, seafood, low fat dairy, beans and other legumes.

Strictly limit: Refined carbs (added sugars, bread, pasta, white rice), processed meat and red meat.


Exercise And Longevity

The Study

The association between exercise habits and longevity was examined in over 116,000 men and women from Harvard’s Nurses’ Health Study and Health Professional Follow-up Study. After 30 years of follow-up, subjects who met the 2018 Physical Activity Guidelines For Americans had a 31% lower risk of cardiovascular disease mortality and a 19% lower risk of dying from any cause. Circulation 2022; 146:523-34.

Take Home Message

The 2018 Physical Activity Guidelines For Americans recommends 75-150 minutes per week of vigorous activity, or 150-300 minutes per week of moderate activity.

Examples of vigorous activity are running, swimming, rollerblading, playing basketball and using an elliptical trainer.

Examples of moderate activity are walking, light bike riding, pushing a lawnmower and water aerobics.

Cardiovascular exercise benefits just about every system in our bodies and reduces risk of just about every major chronic disease. Making time to exercise each day is one of the very best decisions you can make for your physical and mental health.


Dietary Choices And Life Expectancy

Thousands of studies have been published on the risks and benefits of individual foods and health outcomes. For example, red meat has been shown to increase risk of colon cancer. Another example is that whole grains have been shown to decrease risk of coronary heart disease. This type of research is extremely useful and can help guide our dietary recommendations. Now and again, a study is published that looks at the bigger picture and gives us an idea of what happens when you get everything going in the right direction with your diet. 

The Study

This investigation was published earlier this year in PLOS Medicine (Reference #1). It is a meta-analysis of nutrition research that uses life table methodology to estimate how dietary changes impact life expectancy. 

Here are some of the more interesting results from this study:

-An optimal diet was found to be one high in whole grains, fish, fruits, vegetables, legumes and nuts and low in processed meats, red meat, sugar sweetened beverages and refined grains. No big surprises here.

-Switching from a typical Western diet to an optimal diet at age 20 would result in a 10.7 year increase in life expectancy for women and a 13 year increase for men.

-Making this switch at age 40 would result in a 10 year increase in life expectancy in women and 11.7 years in men.

-Making this switch at age 60 would result in an 8 year increase in life expectancy in women and an 8.8 year increase in men.

-Making this switch at age 80 would result in a 3.4 year increase in life expectancy in both men and women.

-Following are the foods most associated with improved life expectancy:

1) Legumes

2) Whole grains

3) Nuts

4) Less red meat

5) Less processed meat

Conclusions And Recommendations

This is a very powerful study that shows just how important that dietary choices are to our health. The main mechanism driving the results of this investigation is that a healthy diet reduces risk of the major chronic diseases, such as heart disease, stroke, type 2 diabetes and cancer.

Another thing to note is that these results only focus on diet and likely underestimate the true effects of an overall healthy lifestyle. In other words, if you don’t smoke, exercise regularly and maintain a healthy weight in addition to eating well, you would likely see even further increases in life expectancy.

As far as recommendations, this study illustrates the benefits of a Mediterranean diet. It is pretty simple to follow: For proteins, focus on lean meats like chicken and turkey, seafood, low fat dairy and vegetable sources of protein such as black beans, lentils and hummus. For fats, focus on vegetable oils, nuts, nut butters and avocados. For carbs, focus on fruits, vegetables, whole grains and legumes.

Limit sugar, bread, pasta, white rice, red meat and processed meats. If you are looking for a great book on the many benefits of eating this way, pick up Dr. Willett’s Eat Drink And Be Healthy. He was the Department Chair at Harvard when I got my doctorate and his book is an unbelievable resource.


1) Fadnes LT, et al. Estimating impact of food choices on life expectancy: A modeling study. PLOS Medicine 2022; 19:e1003889.