Caloric Restriction – December 2024 Newsletter
Caloric Restriction
Hello, this is Dr. Ellen. For many years, there have been a lot of conversations about ways to lose weight for cosmetic reasons as well as to increase health and lifespan. These conversations have progressively increased over the years as the number of those becoming overweight or obese has continued to increase. There has also been increased recognition of many disorders (i.e., comorbidities) that accompany excessive weight, including type 2 diabetes, ischemic heart disease, hypertension, and elevated low-density lipoprotein cholesterol (LDL-C or “bad” cholesterol) blood levels. The phrase ‘increased healthspan’ is more frequently used to express the health benefits of weight loss.
Over the years, various diets, weight loss pills, and surgical interventions have been introduced (many carrying their own risk of significant adverse effects) to attempt to combat the obesity epidemic. The latest innovations to be revealed to the public are the new glucagon-like peptide-1 receptor agonists (GLP-1 RA’s), the two most prominent being semaglutide and tirzepatide injections (Wegovy and Zepbound, respectively, prescribed for obesity with “comorbidity”). These have been touted as a major step forward, not only for weight loss management, but also for improving healthspan and possibly lifespan.
In this month’s newsletter, I want to discuss a weight loss and increased lifespan and healthspan methodology that has been studied for decades, calorie restriction. In particular, I will give an overview of a comprehensive human study that supports caloric restriction’s effectiveness in long term weight loss and improved healthspan, the CALERIE Phase 2 study. This approach, unlike many others, has few if any adverse effects (when not done to an extreme). I will then review what may be an alternative approach to focusing on calories, yet achieving weight loss and health benefits.
By the way, if you haven’t had a chance to see my previous newsletters, you can find them on my website, www.drellencutler.com under ‘Free Resources’.
Prior Research on Caloric Restriction
Food reduction as a means of losing weight has been an accepted fact for millennia. The parallel idea of taking in fewer calories than are expended is generally accepted as a means to lose weight (with some minor modifications, such as the body’s ability to better metabolize breakfast than dinner). More recent discoveries have explored improvements in health and longevity resulting from limiting caloric intake. As early as 1914, a study showed that reducing food intake decreased the development of spontaneous tumors in rodents. Then in the mid 1930’s, a study showed that significantly decreased calorie intake of rats led to longer lifespan compared to those in the control group. This was replicated in a variety of species in the following decades. Since the 1960’s, there have been animal studies attempting to identify the biological reasons for life extension caused by caloric restriction. Some possible explanations include the reduction of body fat, improved immune function, and reduction of blood glucose levels with markedly reduced insulin levels.(1,2)
The CALERIE Phase 2 Study
The CALERIE (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy) Phase 2 study was published in 2015.(3) It was a randomized 2-year intervention with nonobese subjects designed to achieve 25% calorie restriction (CR) in the test group compared to the control subjects who ate without any such restriction. Those in the CR group were taught how to increase the volume of their meals to decrease hunger and how to decrease the fat content and have less calorie density in their foods.(4) After two years, 82% of the CR group and 95% of the unrestricted participants completed the study. The test subjects averaged almost 12% CR over 24 months, with slightly greater than 9% averaged for the latter half of the study period, both well below the initial target. Nonetheless, they maintained more than 10% weight loss at the end of the study, whereas weight change in the control subjects was negligible.
Active thyroid hormone (T3) decreased significantly more in the CR group at both 12 and 24 months. Prior studies had found a relationship between lowered thyroid activity and longevity. C-reactive protein (CRP), an indicator of ongoing inflammation, showed a significantly greater decrease in the CR group. Tumor necrosis factor-α (TNF-α) was also significantly decreased more in the CR group at the end of the study. Elevated TNF-α is known to be associated with inflammation as well as autoimmune diseases, heart disease, and Alzheimer’s disease. The CR subjects also had larger decreases in cardiometabolic risk factors than control subjects. They had significant decreases in triglycerides, total cholesterol, LDL-C, and systolic and diastolic blood pressures. They also had significant increase in high-density lipoprotein cholesterol (HDL-C) compared to control subjects.
Exercise was not controlled during the study and those who had been calorie restricted had larger decreases in daily energy expenditure but without any adverse effects on quality of life. This may have contributed to the small but significant decrease in bone mineral density in the CR group compared to those in the control group. For most in the CR group, there was generally no problem with hunger after about one month, although there was a slight increase in food craving.(4,5) Retrospectively, psychological testing actually revealed modest improvements in mood and level of tension/anxiety.(5)
In spite of not achieving even half of the 25% decrease in caloric intake initially planned, the degree of CR achieved was “tolerable and safe” over two years.(3) The findings were consistent with previous animal studies, suggesting calorie restriction improved human healthspan, which in turn might lead to a resulting increase in lifespan.
Another Interesting Study
In light of the above CALERIE Phase 2 study, another human trial of interest is the BROAD Study published two years later.(6) Subjects categorized as being overweight or obese with at least one comorbidity all received “normal care”. Half of the randomly assigned subjects attended twice-weekly meetings for 12 weeks and followed a whole food plant-based (WFPB) diet that was not calorie restricted as well as being given vitamin B12 supplementation. Interestingly, soy-based foods were to be used sparingly because of their high fat content, if at all, and other foods such as coconuts, avocados, nuts, and seeds (other than an option of up to 2 tablespoons daily of flaxseeds or chia seeds) were not to be consumed.(7) The other half served as the control group. The originally intended 6-month study was extended to 12 months. As in the CALERIE Phase 2 study, exercise was not controlled for either group during the study.
There were two primary parameters evaluated – Body mass index (BMI) (a measure of body fat based on height and weight) and total blood cholesterol. Mean BMI reduction and weight loss was greater in those following the WFPB diet compared to those in the control group. And there was a reduction in total cholesterol for the intervention group in the first 3 months and at 6 and 12 months, compared to the control subjects, who only showed reduction at 3 months. Additionally, the control group medication usage increased from 74 to 80 over 6 months, an 8% increase, whereas intervention group medication usage decreased from 94 to 74 after 6 months, and to 67 over 12 months – a 29% decrease. Hemoglobin A1c (HbA1c), which measures a person’s average blood sugar level over the past 2–3 months, showed greater reduction in the intervention group, especially at 12 months. And two people in the intervention group with diabetes no longer met the diagnostic criteria for diabetes at both 6 and 12 months. There were also significant improvements in quality of life in the intervention group found throughout the 12 months.
In the BROAD study, caloric restriction was not directly encouraged. However, restrictions were placed on foods with high fat content. Also, the increased intake of high fiber foods of a WFPB diet help increase the volume of meals, tending to decrease hunger. These instructions are quite similar to those given to the calorie restricted subjects in the CALERIE Phase 2 study.
Ellen Cutler Method (ECM)
In my clinical practice, I use ECM energetic testing and clearing methods with almost all of my patients. And almost all of the time, I find the optimal dietary pattern for each is a WFPB diet, which I have described in previous newsletters.(8) Especially in those wanting (or needing) to lose weight, decreasing the relative amount of fat in the diet is usually indicated, though oftentimes not to the extent indicated by the BROAD study. In my clinical experience, when adhered to, a WFPB diet typically leads to sustainable weight loss and improved healthspan. And not uncommonly, I hear from patients that adherence to the diet is easier than they initially thought it would be. This is especially true for those using a full spectrum digestive enzyme blend at the beginning of each meal. I usually recommend Dr. Ellen’s Way ‘Digest Supreme’ or, for those with gastrointestinal complaints, Dr. Ellen’s Way ‘G.I. Calm’.
Please be well, be healthy, but remember…
“When you eat mindfully, by paying attention to what you eat, you get more pleasure with fewer calories.”
― Dean Ornish
Dr. Ellen
References:
- “Subfield History: Caloric Restriction, Slowing Aging, and Extending Life” at https://www.science.org/doi/10.1126/sageke.2003.8.re2
- “History of Caloric Restriction, Aging and Longevity” at https://link.springer.com/chapter/10.1007/978-90-481-8556-6_1#:~:text=Sustained%20research%20on%20caloric%20restriction,retarded%20growth%20on%20life%20span
- “A 2-Year Randomized Controlled Trial of Human Caloric Restriction: Feasibility and Effects on Predictors of Health Span and Longevity” at https://academic.oup.com/biomedgerontology/article/70/9/1097/2949096
- “Metabolism, energy balance, and aging: the impact of diet, calorie restriction & macronutrients” at https://www.youtube.com/watch?v=UVGBfrfPq98&t=25s
- “Effects of caloric restriction on human physiological, psychological, and behavioral outcomes: highlights from CALERIE phase 2” at https://pmc.ncbi.nlm.nih.gov/articles/PMC7727025/
- “The BROAD study: A randomised controlled trial using a whole food plant-based diet in the community for obesity, ischaemic heart disease or diabetes” [2017] at https://www.nature.com/articles/nutd20173
- “The BROAD study…” https://www.nature.com/articles/nutd20173 (Supplementary Table S2)
- “Why Vegan?” – June 2022 Newsletter at https://drellencutler.com/june-2022-newsletter/
* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, mitigate, or prevent any disease.
