Researchers say humans may be able to extend their life span by severely limiting caloric intake while packing in the nutrients. What's it like to try this type of nutrition plan?
Paul and Averill McGlothin shared their experience on 20/20 and are answering questions from ABCNews viewers regarding their nutrition choices. For more information, contact the Calorie Restriction Society at www.calorierestriction.org.
Question: How do you handle hunger? Small meals often, snacking or what? -- Alyce Ann Jula Aber Hamburg
Answer: We accept occasional hunger as part of this lifestyle. The hunger sensation is not extreme, and it makes us glad: it's a signal that we are doing what we intend -- eating less fuel than our bodies might crave, so we are more likely to attain our health and longevity goals. We definitely like it better than the bloated feeling of being satiated. Another cause for joy is that when the body is fed fewer calories than it "expects," it goes looking for more. That takes the form of the cells' digesting inclusions that they "didn't bother with before." This results in a cleanup, a sort of cellular level detox. We love it! Our bodies are so smart.
Q.: How do you maintain a low weight, yet still consume enough calories to sustain an exercise program? Also, what research has been done to link the benefits of CR with taming Multiple Sclerosis (MS), which I was diagnosed with 11 years ago. -- Cathy
A.: An intake of 1,900 calories is plenty for me to sustain my (Paul's) weight at my level of exercise activity. I weigh myself regularly and if my weight slips lower than my target of 133, I increase my caloric intake until my weight is stable. We don't have an answer for you about MS but recommend that you keep an eye on the work of researcher Mark P. Mattson. His work on Brain Derived Neurotrophic Factor may be especially interesting. Searching on multiple sclerosis and BDNF in www.Pubmed.gov (the National Library of Medicine's online access) ought to be useful. It turns out that discussions have appeared about MS and CR on http://calorierestriction.org/ and can be found in the archives on the site.
Q.: I run about 60 miles per month and weight lift. While the CR lifestyle appeals to me, I don't think I would be consuming enough calories to remain strong while exercising.
A.: There are all levels of CR, so it's not necessary to restrict like we do to get some benefits. Studies show that CR gives far more longevity benefits than exercise, though, so we personally follow a moderate exercise program -- making it easier to sustain our limited calorie intake.
Q.: Will you be telling the viewers what foods you eat to maintain good health; do these foods satisfy hunger; and, do you exercise regularly? Thank you. -- Suzanne Lexington, Ky.
A.: We eat nutrient-dense foods, such as protein (salmon, brewers' yeast, etc.) and low glycemic carbs (cabbage, broccoli, collards, and the like), as well as fruit (pears and apples, for example) and fats (egg yolk a couple times a week, walnuts daily, olive oil, etc.) These foods satisfy hunger when eaten, but we do get hungry, and that's when we know that our bodies are detoxifying themselves at the cellular level.
On a daily basis we exercise moderately (run-walk) and twice a week more vigorously for aerobics and weight training.