Comparison of High-Protein, Intermittent Fasting Low-Calorie Diet and Heart Healthy Diet for Vascular Health of the Obese

Abstract

Aim: It has been debated whether different diets are more or less effective in long-term weight loss success and cardiovascular disease prevention among men and women. To further explore these questions, the present study evaluated the combined effects of a high-protein, intermittent fasting, low-calorie diet plan compared with a heart healthy diet plan during weight loss, and weight loss maintenance on blood lipids and vascular compliance of obese individuals.Methods: The experiment involved 40 obese adults (men, n = 21; women, n = 19) and was divided into two phases: (a) 12-week high-protein, intermittent fasting, low-calorie weight loss diet comparing men and women (Phase 1) and (b) a 1-year weight maintenance phase comparing high-protein, intermittent fasting with a heart healthy diet (Phase 2). Body weight, body mass index (BMI), blood lipids, and arterial compliance outcomes were assessed at weeks 1 (baseline control), 12 (weight loss), and 64 (12 + 52 week; weight loss maintenance).Results: At the end of weight loss intervention, concomitant reductions in body weight, BMI and blood lipids were observed, as well as enhanced arterial compliance. No sex-specific differences in responses were observed. During phase 2, the high-protein, intermittent fasting group demonstrated a trend for less regain in BMI, low-density lipoprotein (LDL), and aortic pulse wave velocity than the heart healthy group.Conclusion: Our results suggest that a high-protein, intermittent fasting and low-calorie diet is associated with similar reductions in BMI and blood lipids in obese men and women. This diet also demonstrated an advantage in minimizing weight regain as well as enhancing arterial compliance as compared to a heart healthy diet after 1 year.

Effects of intermittent fasting on glucose and lipid metabolism

“…Compliance is reportedly high (29,37) , with both acute (5) and chronic (29,30,37,40) studies demonstrating a lack of full compensatory hyperphagia following modified fasting days. In overweight/ obese (26)(27)(28)(29)(30)(31)(32)(33)(34)(35)37,38,40,41) or combined healthy/overweight (36) cohorts, the average reported weight-loss through IER (70-100 % energy restriction) has ranged between approximately 4 and 10 % over dieting periods of 4-24 weeks. There are also some data demonstrating the successful applications of IER as a weight-maintenance strategy following weight-loss for periods of up to 1 year (37,39) .…”

“…To date, all IER studies allowing fast day intake have solely measured fasting blood markers of cardiometabolic risk. Some (27,(30)(31)(32)(33)(35)(36)(37)41) but not all of these studies (28,29,34,40) have included CER (standard treatment) or ad libitum (no intervention) control groups, whilst others have compared two or more different IER protocols (35,38,39) . In individuals with T2DM, IER has been shown to improve glycaemic control and lipid profiles (27) .…”

“…100 % energy restriction) every other day, with fasting intervals ranging between 20 and 36 h. However, the long-term sustainability of this alternate day total fasting approach in human subjects is questionable due to the persistent hunger reported (24) . Subsequently, the IER protocols used by most human studies (27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41) , and by some rodent studies (11,14,42) , have allowed a small amount of 'fast' day intake, so that energy is substantially (⩾70 %) but not completely restricted. This is often referred to as modified fasting, such that, the term fasting in this IER context denotes periods of severe (total or partial) energy restriction.…”

“…This is often referred to as modified fasting, such that, the term fasting in this IER context denotes periods of severe (total or partial) energy restriction. These modified fasting forms of IER have predominantly been utilised as weight-loss strategies, whilst a small number of studies have also used protocols intended to encourage weight maintenance (37,39,41) . The most well-studied examples include alternate day modified fasting and the 5:2 diet, which entails two modified fast days a week (Table 1), although many variations exist.…”

“…The most well-studied examples include alternate day modified fasting and the 5:2 diet, which entails two modified fast days a week (Table 1), although many variations exist. Intakes on non-restricted ('feed') days among these studies have ranged from ad libitum (27)(28)(29)(31)(32)(33)(34)36,38) , hypoenergetic (approximately 15-30 % of energy requirements) (34,41) , isoenergetic (30,37,40) or hyperenergetic (approximately 125-175 % of energy requirements) (35,39) . Compliance is reportedly high (29,37) , with both acute (5) and chronic (29,30,37,40) studies demonstrating a lack of full compensatory hyperphagia following modified fasting days.…”