By Danielle Sharkey a recent ASU Nutrition student
Introduction
The Ketogenic diet has been a very popular and highly promoted diet for rapid weight loss and the fight against obesity. The diet follows an extremely high-fat and low-carb regimen where about 75% (or between 70% and 85%) of your calories are consumed in healthy fat form, while 15-20% comes from protein, and the last 5-10% of your calories comes from carbohydrates. This has been proven to be a very hard regimen to follow but the results have been positive and frequent for weight loss over a short period of time. (1) When consuming 75% of your calories from fat, the blood glucose levels drop immensely, satiety increases which decrease appetite, energy levels spike, and weight loss is influenced. Healthy and overweight women, up to the age of 50, will most likely benefit from implementing a Ketogenic diet (high-fat; low-carb) over at least a 10-week time period, by losing weight and improving body composition.
High Ketone-Levels in the Blood
A high-fat, ketogenic diet raises ketone levels in the blood, thus lowering glucose levels which helps to reduce the cravings for sweet/starchy foods. The less these types of food are eaten, the more potential for loss of weight. (2) Ketogenic diets shift your body into a fasting-like state. This happens from the extreme lack of carbohydrates accessible for fuel. As a result, your body turns to fat for use as an alternative fuel (this elevates ketone levels in the blood). (2) This means that your body is burning your excess fat constantly in order to fuel your system. The state that the body is in is called ketosis. In one study, there was a significant difference in cravings for starchy and fast-foods with the Ketogenic group reporting less cravings. (2) Low-carb diets (high-fat) not only lower blood glucose levels but they have been overall more effective in losing weight than low-fat diets. With these limited glycogen stores from the large restriction of carbohydrates in the diet, loss of fat is greater than when carbs are not restricted. (2) We know that glucose levels lower while ketone levels rise in the body during ketosis. This process then influences fat oxidation (or the melting away of fat) while changing body composition throughout the entire body.
Fat Oxidation
When ketone levels rise in the blood and the body goes into ketosis, capillary beta-hydroxybutyrate (βHB) increases fat oxidation rates… showing higher rates of fat loss, loss of visceral fat and fat tissue around organs. Researchers wanted to test how a ketogenic diet conserved lean body mass while reducing body fat in women who also implemented a resistance training regimen. Eighteen untrained women volunteers, ages 20 to 40 (BMI≥ 25kg*m^-2) were randomly assigned to a group that followed a regular diet and a group that followed a strict Ketogenic diet. 66% of the KD energy was from fat, 22% from protein, and 6% was from carbohydrates. (3) Lean body mass (mass from the muscles) was not affected by this study but the KD group lost almost twice the amount of fat compared to the regular diet group. Blood lipid levels were tested the morning after an overnight fast. All subjects in the KD group lost weight while the regular diet (RD) group had a non-significant increase in body weight. The KD group lost on average 6-9 lbs. in the 10-week process while the RD group lost on average .6 kg. That is an extremely large difference. The subjects that were following the ketogenic diet regimen lost a substantial amount of visceral fat, fat around the organs, and all over fat mass. (3) While this study was done with the implementation of resistance training (twice a week 60-100 min each session), this study still validates the significance of the Ketogenic diet has on weight loss over a shorter time period.
Increased Energy Levels
While ketone levels rise in the blood, fat is then used for energy. Studies have shown that while following an intense ketogenic diet, energy spikes as you are burning your bodies fat stores. (4) This increase in energy allows the potential for higher intensity work-outs which then allows the possibility for a better result in weight loss and body composition while implementing the KD.
Conclusion
A Ketogenic diet increases ketone levels in the blood, increases satiety, decreases appetite, lowers blood glucose levels, curbs bad cravings, increases metabolism and boosts energy, and is an overall effective weight loss method (short-term) in women. (5) Although, a diet that is not extremely restrictive when it comes to carbohydrates (that implements more fruits and vegetables) is going to be more nutritionally sufficient for a long-term way of eating, a high-fat Ketogenic diet is going to be more effective for weight loss in the short term. The interesting thing is, there is difficulty not being able to find too many randomized control trials specifically on the Ketogenic diet and weight-loss in the female gender. Within most papers that have been implemented within the research of this one, the subjects seem to have extra circumstances going on– i.e. ovarian/endometrial cancer, diabetes, epilepsy, etc. It was more difficult to find trials specifically focused on weight loss in healthy women (non-obese). More studies need to be conducted over a longer period of time in order to sufficiently prove whether or not KD diet is a sustainable method for weight-loss over many years of application or if it is sustainable over any extended period of time. It could be suggested that implementing a strict Ketogenic diet over at least a 10 week period will be highly effective when the end goal is to lose fat mass and improve your body composition.
Fill you plate has covered the Keto diet a lot in the past year.
Looking for more tips and tricks like this to keep you family happy and healthy? Check out the Fill Your Plate Blog. Looking for some new recipes to try out? Check out the Recipe Section of our website. How about some fresh produce that the whole family will enjoy? Check out the local Farmers Markets near you.
References
1.) Cohen, C. W., Fontaine, K. R., Arend, R. C., Alvarez, R. D., Iii, C. A., Huh, W. K., . . . Gower, B. A. (2018). A Ketogenic Diet Reduces Central Obesity and Serum Insulin in Women with Ovarian or Endometrial Cancer. The Journal of Nutrition, 148(8), 1253-1260. doi:11.1093/jn/nxy119
2.) Cohen, C., Fontaine, K., Arend, R., Soleymani, T., & Gower, B. (2018). Favorable Effects of a Ketogenic Diet on Physical Function, Perceived Energy, and Food Cravings in Women with Ovarian or Endometrial Cancer: A Randomized, Controlled Trial. Nutrients, 10(9), 1187. doi:11.3390/nu10091187
3.) Iacovides, S., & Meiring, R. M. (2018). The effect of a ketogenic diet versus a high-carbohydrate, low-fat diet on sleep, cognition, thyroid function, and cardiovascular health independent of weight loss: Study protocol for a randomized controlled trial. Trials, 19(1). doi:11.1186/s13063-018-2462-5
4.) Jabekk, P. T., Moe, I. A., Meen, H. D., Tomten, S. E., & Høstmark, A. T. (2010). Resistance training in overweight women on a ketogenic diet conserved lean body mass while reducing body fat. Nutrition & Metabolism, 7(1), 17. doi:11.1186/1743-7075-7-17
5.) Josse, A. R., Atkinson, S. A., Tarnopolsky, M. A., & Phillips, S. M. (2011). Increased Consumption of Dairy Foods and Protein during Diet- and Exercise-Induced Weight Loss Promotes Fat Mass Loss and Lean Mass Gain in Overweight and Obese Premenopausal Women. The Journal of Nutrition, 141(9), 1626-1634. doi:11.3945/jn.111.141028
6.) Stomby, A., Simonyte, K., Mellberg, C., Ryberg, M., Stimson, R. H., Larsson, C., . . . Olsson, T. (2014). Diet-induced weight loss has chronic tissue-specific effects on glucocorticoid metabolism in overweight postmenopausal women. International Journal of Obesity, 39(5), 814-819. doi:11.1038/ijo.2014.188