Study under review: A heterogeneous response of liver and skeletal muscle fat to the combination of a Paleolithic diet and exercise in obese individuals with type 2 diabetes: a randomised controlled trial.
Type 2 diabetes is a metabolic disorder characterized by a resistance to insulin, leading to a reduced ability of muscle and fat cells to properly uptake glucose and consequently resulting in chronically high levels of blood glucose. The prevalence of both type 1 and type 2 diabetes is estimated to be 12%-14% of the U.S. population. Globally, recent estimates indicate a prevalence of 8.8% in 2015 that is expected to grow to 10.4% by 2040, with 90% of all cases estimated to be type 2 diabetes.
Obesity, particularly abdominal obesity, is very strongly associated with type 2 diabetes. Type 2 diabetes has also been shown to be correlated with non-alcoholic fatty liver disease, visceral fat, inflammatory cytokines like interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα), and an elevated intramyocellular lipid (IMCL) content (i.e. fat in the skeletal muscle).
Diet and lifestyle interventions have been shown to be very effective at sustainably reducing the incidence of type 2 diabetes. These interventions, which require significant diet and lifestyle modifications, can even be more effective than first line diabetes drugs like metformin at reducing the risk of developing type 2 diabetes. A recent meta-analysis concluded that interventions with diet modification and exercise that included both aerobic and resistance training were the most effective at reducing biomarkers of type 2 diabetes. However, limited evidence suggests that interventions that include both exercise and diet perform as well as exercise alone.
Public interest in Paleolithic-style diets has increased dramatically over the past several years. Just like the "Mediterranean diet," the "Paleo diet" is not a detailed dietary prescription, but rather a set of rules that requires one to consume a diet consisting largely of meats, vegetables, fruits, nuts, and tubers, while excluding cereal grains, dairy, and products with added salt and sugar.
In people with type 2 diabetes, the Paleo diet has performed favorably against diets based on national dietary guidelines, the Nordic Nutrition Recommendations, and a standard low-fat diet in clinical trials. The study under review would be the first to examine the differences between a Paleo diet alone and a Paleo diet with a combination of aerobic and resistance exercise.
Type 2 diabetes is a growing problem in the U.S. and globally. Treating type 2 diabetes with diet and exercise has been shown to be very effective, but few studies have focused on treatments with a Paleolithic-style diet and none have examined the effect of adding exercise to this diet and the differential effects on liver fat and intramuscular fat stores.
Other Articles in Issue #48 (October 2018)
Interview: Bill Willis, PhD
What the heck is HMGB1 and why care about it? In this interview, we pick the brain of Examine.com researcher Bill Willis about a recent paper he published on the matter, and get his insights on the research process and his opinion on the recent spate of scientific misconduct reports.
Mini: Vitamin D, dementia, and lipids: the ApoE connection
In this mini, we give you a quick summary of recent research examining how ApoE genotype affects the way blood lipids respond to swapping out dietary saturated fat for carbs.
Can keratin supplementation improve body composition and cycling performance in endurance-trained men?
Getting your protein from feathers and hooves doesn't sound very tasty. Nor is it practical, since we can't digest them. However, sulfur-rich keratin can be extracted from these livestock-processing byproducts. Does it have any practical advantages over casein?
Which diet’s best for weight and metabolic risk factors in people with type 2 diabetes?
There's quite a bit that's known about how diets impact diabetes. What's less well understood is how different diets compare. This network meta-analysis aimed to find out.
CoQ10 supplementation helps with one pole of bipolar disorder
There's reason to believe that coenzyme Q10 supplementation can impact on unipolar depression. This trial looked at whether it could also improve depression in people with bipolar disorder when added to standard treatment.
Elderly people at risk for dementia may benefit from vitamin D supplementation
Not everyone with mild cognitive impairment (MCI) proceeds progresses to dementia, but the majority do. Can vitamin D supplementation help with cognition in people with MCI?
Can alpha lipoic acid help manage metabolic diseases?
We've previously covered a meta-analysis looking at ALA's impact on weight. But how much of an impact does it make on cholesterol and glycemic control?