|Study suggests: Your goals may determine whether a low or high fat diet is the better base for alternate day fasting.|
Against that background it may be worth taking a look at a bunch of recent studies; starting today with one that investigates the pros and cons of high vs. low fat dieting on an alternate fasting regimen (Varady. 2015) - pros and cons of which the study results indicate that they may depend on your goals.
Weight loss is one goal you may want to achieve by dieting is weight loss. Another, eventually more important goal is to improve your health. The latter, i.e. improving your health by lowering / improving the free fatty acid profiles via alternative day fasting was the research interest of scientists from the University of Illinois at Urbana-Champaign. In their latest experiment, Varady et al. examined how alternative day fasting (ADF) diets of different macronutrient compositions affect plasma FFA profiles in the context of weight loss, and changes in body composition and lipid profiles.
|Figure 1: Changes in body composition in response to low vs. high fat alternative day fasting containing 25% or 45% of the 75% energy reduced diet on the fasting day in form of fat (Varaday. 2015).|
- 25% of the required energy on the fasting day (day 1, 3, 5, ...),
- 125% of the required energy on the feast days (day 2, 4, 6...) and
- had the same macro composition on both days,
|Alternative day fasting may also have cancer protective anti-proliferative effects (Varaday. 2008).|
Negative, because cancer patients tend to lose weight rapidly. True fasting, alternative day fasting with zero energy intake on the fasting day and chronic energy restriction would thus only promote their risk of ending up "muscle less" and bedridden (Fearon. 2011).
|Figure 2: Exact macronutrient composition in grams for someone consuming 2000kcal per day; in % that's 45/15/40% fat, protein carbohydrate for the high fat and 25/15/60% for the low fat group (Varaday. 2015 as in Klempel. 2014)|
And here the low fat alternate day fasting diet had significant advantages.
|Figure 3: Changes in total cholesterol LDL, triglycerides, HDL (no change!) and glucose (Varaday. 2015).|Learn more about alternate day fasting in general in a previous SuppVersity article.
- impair glucose uptake and will thus increase the risk of developing type II diabetes, which in turn is one of the major risk factors for developing the metabolic (Boden. 1994),
- especially high levels of palmitic acid (saturated fatty acid) are associated with increased risk of triglyceridemia and abdominal obesity which in turn are linked to cardiovascular disease risk (Paillard. 2008).
Thus the effects of e.g. higher omega-3 intakes (in the study at hand total PUFA was 25g and 12g in the high fat and low fat group), as well as the effects of higher protein intakes, specifically on the fasting days, where someone with a baseline intake of 2,000kcal would consume only 18.75g protein and thus way too little for optimal lean mass retention are in fact parameters that would have to be studied in future studies.
- Boden, Guenther, et al. "Mechanisms of fatty acid-induced inhibition of glucose uptake." Journal of Clinical Investigation 93.6 (1994): 2438.
- Fearon, Kenneth, et al. "Definition and classification of cancer cachexia: an international consensus." The lancet oncology 12.5 (2011): 489-495.
- Heilbronn, Leonie K., et al. "Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism." The American journal of clinical nutrition 81.1 (2005): 69-73.
- Klempel, Monica C., Cynthia M. Kroeger, and Krista A. Varady. "Alternate day fasting (ADF) with a high-fat diet produces similar weight loss and cardio-protection as ADF with a low-fat diet." Metabolism 62.1 (2013): 137-143.
- Paillard, François, et al. "Plasma palmitoleic acid, a product of stearoyl-coA desaturase activity, is an independent marker of triglyceridemia and abdominal adiposity." Nutrition, Metabolism and Cardiovascular Diseases 18.6 (2008): 436-440.
- Pilz, Stefan, et al. "Elevated plasma free fatty acids predict sudden cardiac death: a 6.85-year follow-up of 3315 patients after coronary angiography." European heart journal 28.22 (2007): 2763-2769.
- Varady, Krista A., et al. "Modified alternate-day fasting regimens reduce cell proliferation rates to a similar extent as daily calorie restriction in mice." The FASEB Journal 22.6 (2008): 2090-2096.
- Varady, Krista A., et al. "Effects of weight loss via high fat vs. low fat alternate day fasting diets on free fatty acid profiles." Scientific Reports 5 (2015).