The Endocrine Society's 98th Annual Meeting & Expo:
Paleolithic-Type Diet May Help Postmenopausal Women Lose Weight
A Paleolithic-type diet with a high content of unsaturated fatty acids and low content of carbohydrates may help healthy obese postmenopausal women lose weight. "We found that Paleolithic-type diet reduced specific fatty acids in the blood associated with insulin resistance more distinctly than a controlled diet, despite similar weight loss. The Paleolithic-type diet may have long-term beneficial effects on obesity-related disorders such as insulin resistance and cardiovascular diseases," said lead study author Caroline Blomquist. Ms. Blomquist is a doctoral student in the Department of Publish Health and Clinical Medicine, and Assistant Professor in the Department of Ecology and Environmental Sciences at Umeå University in Sweden.
After menopause, women have an increased risk of abdominal obesity associated with a reduction of estrogen production. Dietary fatty acids influence adipose tissue function, as well as whole body metabolism. "We have analyzed fatty acid composition in blood during a diet intervention. Saturated fatty acids can stimulate the production of pro-inflammatory factors in fat cells. These pro-inflammatory factors can induce a low brain inflammatory state in the body, resulting in decreased insulin sensitivity and cardiovascular diseases. Polyunsaturated fatty acids [PUFAs] from, for example, fish can have beneficial effects on insulin sensitivity by affecting specific genes in muscle and the liver. PUFAs can also reduce inflammation and appetite," explained Ms. Blomquist.
Study Subjects and Methods
Blomquist and her colleagues studied 70 obese postmenopausal women with ave age BMI of 32.6 and randomly assigned them to one of two groups: Paleolithic-type group (PD group) and controlled diet group (CD group). The study period was 24-months for each group.
Participants in the PD group aimed to consume 30% of protein, 30% of carbohydrates and 40% fat, including a high content of unsaturated fatty acids," said Ms. Blomquist.
- The Paleolithic-type diet was based on lean meat, fish, vegetables, fruits, nuts, and berries. Rapeseed, olive oil, and avocado were additional fat sources.
- Dairy products, cereals, as well as added salt, refined fat and sugar were excluded.
The women in the CD group aimed to eat 15% of protein, 55% of carbohydrates, and 30% in fat.
After 6 months, weight reduction was greater in the PD group. However, at 24 months, women in both groups lost a significant amount of body weight, including abdominal obesity.
- Self-reported intake of food can be biased; therefore, biomarkers, such as fatty acids in the blood, were evaluated.
- Fish intake increased in both diet groups. But there was a significant difference at 6 months with the high intake of fish in the PD group. Fish intake was associated with an increased unsaturated fatty acid intake, which is associated to the insulin sensitivity.
- Delta-9-desaturase is an enzyme in liver that is associated to increased liver fat, insulin resistance, and mortality. Blomquist and colleagues found the index for this enzyme was reduced in the Paleolithic-type group during the entire intervention.
"The Paleolithic-type diet reduced specific fatty acids and desaturase activities associated with insulin resistance more distinctly than a controlled diet, despite similar weight loss. The changes in fatty acid levels associated to a Paleolithic-type diet may have long-term beneficial effects on obesity-related disorders," concluded Ms. Blomquist.