Follow us 182.0k

People start following a ketogenic diet many different reasons: to lose weight or manage a health condition - eg by reducing severity of seizures in drug-resistant epilepsy. In this article, we examine the role of insulin sensitivity in our diet and look at how it affects weight loss.

The Ketogenic Diet and Insulin-Resistant Patients

That scene in Shameless when the nurse tells Kev his tumor is benign and he says:

“Oh god no … Wait is that good or bad, I can never remember” hahaha

The authors of this manuscript called their dietary intervention “benign dietary ketosis” (+1), which turned out to be a pretty big understatement given the conclusion:

“All variables for the ketogenic group out-performed those of the exercise and non-exercise groups, with five of the seven [pre-specified endpoints] reaching statistical significance” ( Gibas and Gibas, 2017).

They cited the Dashti year-long keto study which showed a significant reduction in antidiabetic meds before significant weight loss ( Dashti et al., 2006). This is keto’s strong suit: obese insulin resistant (IR) subjects.

The #1 Keto Diet App Free Download 1,500+ delicious keto recipes Trialed & tested for best results Optimized for nutrition Never feel hungry Planner & tracker Track all macros including net carbs Scan products Create your own meals Advanced tracking Track ketones, blood glucose & lipids Stay hydrated with water tracking Track your mood & energy levels Macro calculator Calculate your ideal fat, protein & carb intake Set any goal: weight loss, maintenance or weight gain Your macros update based on your progress Progress Monitor your macros, water intake, mood & energy Body weight, body fat and body measurements Ketones, blood glucose & lipids Evidence-based content Expert articles to help you make informed choices Guides & free diet plans New daily content And so much more...! Complete Keto Diet guide Integrated shopping basket Restaurants & guide to eating out Free Download App Store Google Play App Store Also available on Google Play Google Play Also available on App Store

Insulin resistance is carbohydrate intolerance which means that more insulin is needed to metabolize carbs. More insulin then leads to an increased fat storage.

In Gibas and Gibas, they selected the right population (obese IR) and kept carbs below 30 grams per day. This was confirmed as ketones continued to increase all the way through week 10.

This demonstrates better-than-average adherence to the dietary advice. Usually the opposite happens whereby participants begin with very low carbs, a large energy deficit, and rapid weight loss (all of which are conducive to deep ketosis), and as the study goes on, carb creep, smaller energy deficit, and slowed weight loss (all of which lower ketones). Cool.

The Comparison Groups

Keto diet – participants were eating up to 30 grams of carbs per day for 10 weeks. No diet intervention which is basically a weight-maintaining control group (commonly overlooked but important control group because just the simple act of being in a diet study usually causes people to lose weight); and No diet intervention plus exercise (30 minutes of exercise 3-5 times a week).

Strengths of the Study

Data presentation was excellent: individual values and averages were reported. This is important because it is visually easy to see inter-individual variability in the responses. Body weight, body fat, BMI, HbA1c, and triglycerides were all significantly reduced in the keto group compared to the exercise and non-exercise groups.

Another strength of this study is that all diets were to be consumed ad libitum - they could eat as much as they wanted, so it more closely reflected what would happen in real life, outside the setting of a clinical study.

Short-comings of the Study

The main short-coming in this manuscript is the lack of information about the diets (foods, macro’s, calories, etc.). However, we don’t expect too much change in the control groups, which was confirmed by the lack of weight loss, and elevated ketones in the keto group confirms good adherence, at least, to the carbohydrate advice.

Another short-coming is the exercise intervention in the third group which I suspect was quite weak as we know exercise is beneficial although no clinical improvements were seen in this group. Exercise alone doesn’t usually result in significant weight loss because energy intake frequently increases or total energy expenditure declines to compensate.

The fact that exercise alone doesn’t result in significant weight loss was demonstrated in the notorious marathon study, wherein previously sedentary participants trained for a marathon for 18 months and eventually ran a marathon - we know they exercised a lot because a marathon is no small feat ( Janssen et al., 1989)!

But no weight was lost because no dietary advice was given - they simply instinctively ate more. No major changes in body composition occurred because that isn’t usually observed in the absence of resistance training in this context.