Intermittent fasting 5:2 diet: What is the macronutrient and micronutrient intake and composition?

BACKGROUND & AIM: Intermittent fasting (IF) is a dietary intervention that has been investigated as an alternative weight-loss diet due to conventional approaches having poor long-term adherence. However, the macronutrient and micronutrient intake and composition of IF diets have been overlooked. The primary aim of this study was to describe the macronutrient and micronutrient intake of individuals following the 5:2 intermittent fasting diet (IF 5:2). METHODS: Thirty eight overweight and obese participants were included from two previous studies of IF 5:2. The participants selected included 27 males and 11 females, with and without Type 2 Diabetes. The dietary intervention, IF 5:2, consisted of two days per week fasting, either consecutive or non-consecutive, and five days per week of habitual intake. Prospectively completed 4-day estimated food records were used to assess macronutrient and micronutrient intake at baseline and week six. The 4-day records were weighted to give a mean daily intake during IF 5:2. RESULTS: During IF 5:2 the median (25th, 75th quartile) daily macronutrient composition was 22 (19, 24)% from protein, 33 (29, 37)% from fat and 39 (36, 43)% from carbohydrates. The intake (g/d) of carbohydrates and fibre decreased significantly from baseline to week six (p < 0.001) as well as on fasting days compared to non-fasting days (p < 0.001). The intake of calcium, zinc, magnesium and potassium were lower than recommended guidelines. Sodium intake exceeded the suggested daily target. On fasting days, the percent of total energy from protein significantly increased from 21% to 25% (p = 0.02). Despite intake being unrestricted on non-fasting days the energy intake decreased by week six when compared with baseline. CONCLUSION: The composition of IF 5:2 was a high protein, moderate fat, low carbohydrate diet with a low fibre intake. Some micronutrients have lower than recommended intake. However, overall IF 5:2 is a safe acceptable weight-loss diet strategy.

Intermittent fasting in Type 2 diabetes mellitus and the risk of hypoglycaemia: a randomized controlled trial.

AIMS: To establish whether the risk of hypoglycaemia is greater with 2 consecutive days of very-low-calorie diet compared with 2 non-consecutive days of very-low-calorie diet in people with Type 2 diabetes. METHODS: This was a non-blinded randomized parallel group interventional trial of intermittent fasting in adults. The participants had a BMI of 30-45 kg/m2 , Type 2 diabetes treated with metformin and/or hypoglycaemic medications and an HbA1c concentration of 50-86 mmol/mol (6.7-10%). The participants followed a 2092-2510-kJ diet on 2 days per week for 12 weeks. A total of 41 participants were randomized 1:1 to consecutive (n=19) or non-consecutive (n=22) day fasts, of whom 37 (n=18 and n=19, respectively) were included in the final analysis. The primary outcome was difference in the rate of hypoglycaemia between the two study arms. Secondary outcomes included change in diet, quality of life, weight, lipid, glucose and HbA1c levels, and liver function. RESULTS: The mean hypoglycaemia rate was 1.4 events over 12 weeks. Fasting increased the rate of hypoglycaemia despite medication reduction (RR 2.05, 95% CI 1.17 to 3.52). There was no difference between fasting on consecutive days and fasting on non-consecutive days (RR 1.54, 95% CI 0.35 to 6.11). Improvements in weight, HbA1c , fasting glucose and quality of life were experienced by participants in both arms. CONCLUSIONS: In individuals with Type 2 diabetes on hypoglycaemic medications, fasting of any type increased the rate of hypoglycaemia. With education and medication reduction, fewer than expected hypoglycaemic events occurred. Although it was not possible to determine whether fasting on consecutive days increased the risk of hypoglycaemia, an acceptable rate was observed in both arms.

Hypoglycaemia-induced myocardial infarction as a result of sulphonylurea misuse.

BACKGROUND: Recent large-scale randomized trials of intensive therapy in Type 2 diabetes have reported increased cardiovascular morbidity and mortality in patient populations who experience a high frequency of hypoglycaemic events. However, there are few descriptions of hypoglycaemia leading directly to a myocardial infarction (MI) in the medical literature to date. CASE REPORT: In this article we describe the case of a 76-year-old woman without diabetes who presented with symptoms, left bundle branch block and raised troponin, indicative of an MI. She was also noted to be hypoglycaemic with a plasma glucose level of 2.5 mmol/l. It was subsequently discovered that she had mistakenly been dispensed glibenclamide, a long-acting sulphonylurea, in the preceding weeks. Her cardiac symptoms resolved completely upon treatment of her hypoglycaemia and she had no significant coronary artery disease on angiography. CONCLUSION: This is the first case of sulphonylurea-induced MI in a patient without diabetes and illustrates the adverse effects of acute hypoglycaemia upon the cardiovascular system.