Older people with obesity are at a particularly high risk of developing diseases such as type 2 diabetes and cardiovascular disease. Rather than total fat mass, fat deposition in certain areas, such as the abdominal cavity and skeletal muscle, may confer this increased risk of developing the disease. A new study, published in Nutrition and Metabolism, by University of Alabama researchers at the Nutrition Obesity Research Center in Birmingham, observed improvements in body composition, fat distribution and metabolic health in response to an eight-week diet very low in carbohydrates. The lead author of the study is Amy Goss, PhD, RDN, a professor in the UAB Department of Nutrition Sciences. Goss says his team aimed to determine whether a very low-carb, or VLCD, high-fat diet would deplete these fat stores and preserve lean mass without intentional calorie restriction in older adults with obesity, thereby improving outcomes. related to cardiometabolic disease, such as insulin sensitivity and lipid profile.
After the eight-week surgery, despite the recommendation to follow a weight maintenance diet, the very low carb diet group lost more weight and total fat mass than the control diet group. The consumption of eggs was an important part of the VLCD prescription. The team provided eggs to participants in this diet group and asked them to consume at least three per day. Although eggs were part of this study, scientists cannot yet conclude that their results are the result of daily egg consumption; but they may conclude that whole eggs can be incorporated into the diet in a healthy way without negatively affecting blood cholesterol in the elderly. The main difference in fat lost between the two groups was from the abdominal cavity and skeletal muscle stores. The researchers also found significant improvements in the overall lipid profile (cholesterol and triglycerides). Additionally, insulin sensitivity improved in response to the very low-carb diet, reflecting a reduced risk of type 2 diabetes.
Overall, improvements in body composition, fat distribution, and metabolic health have been reported in response to an eight-week ultra-low-carb diet. VLCD is a treatment option for many conditions, including type 2 diabetes, obesity, and non-alcoholic fatty liver disease. This study extends previous research to show that it may be a safe treatment option for the 70-year-olds suffering from obesity. This is the first study to demonstrate the depletion of “metabolically damaging” fat deposits while preserving skeletal muscle, during weight loss in response to a VLCD in the elderly. There is a lot of evidence on the benefits of a very low-carb diet in younger people and this study was one of the first to test this dietary approach to improve obesity-related outcomes in adults over the age of 65. This population has a particularly high risk of other diseases and requires therapeutic interventions to improve health by preserving muscle mass to prevent or delay functional decline with age.
Historically, eggs have gotten a bad rap since the nutrition guidelines on egg consumption set out by the American Heart Association in 1968. It is recommended that you consume no more than three whole eggs each week. The concern stems from saturated fat and egg yolk cholesterol (about 300 mg). Since then, these recommendations have eased as more recent research has shown the negligible impact of dietary cholesterol on blood cholesterol. However, clinicians have forgotten from Biochemistry fundamentals that HMG-CoA reductase, the limiting enzyme for the nove cholesterol synthesis, in inhibited in a negative feeedback by cholesterol itself. This means that dietary cholesterol in not the real problem; our body prefers to accumulate cholesterol from acetyl-coenzyme A derived from glucose breakdown (glycolysis). It’s carbohydrate dietary overload that puts the basis for an excessive cholesterol production. Last August, the Dietary Guidelines Advisory Committee issued recommendations for increasing egg consumption throughout life, including pregnant and lactating women, and also as a first food for babies and young children.
The Committee recognized eggs as an important and nutrient-rich food source, as eggs are a rich source of protein, choline, vitamin B12, selenium, vitamin D, and a long list of other nutrients vital for growth and development, as well as for the maintenance of muscle mass. From here it can be deduced that eggs can be safely consumed at an altitude of at least one per day. There is no dedicated scientific evidence that consuming more than three eggs a week raises blood cholesterol. Swedish studies published in the last three years have also shown that there is no difference in danger between HDL cholesterol (the one considered “good”) and LDL (called the “bad”). Excessive HDL cholesterol would also be a cardiovascular risk factor. And we must not forget that the notions of biochemistry of 1970 are not those of 2020. Fifty years of field research have shown that metabolism can work in unexpected ways that sometimes contradict the old notions of the past.
- Edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
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