Time-restricted feeding (TRF) and Ramadan fasting (RF) have been recently associated with several health outcomes. However, it is not yet clear if they are superior to existing treatments in terms of glucose metabolism, insulin action, and weight loss. This review aims to summarize the current data on the effects of these regimes on body weight, body composition, and glycemia. An electronic search was conducted in PUBMED and SCOPUS databases up to August 2022. Twenty-four records met the inclusion criteria and underwent a risk-of-bias assessment. The main outcomes were: (a) TRF may result in moderate weight loss in individuals with overweight/obesity; when TRF is combined with caloric restriction, weight loss is >5% of the initial body weight, (b) 14 h of fasting may be as effective as 16 h in terms of weight loss, and (c) TRF may lead to improved insulin sensitivity and glycemic responses/variability throughout the day in individuals with overweight/obesity. Concerning RF, only two studies were available and thus, conclusions were not drawn. TRF may be an effective nutritional approach for weight loss, and the amelioration of glycemic control and insulin sensitivity in individuals with overweight/obesity. However, more long-term, well-designed studies are needed.

This study examined the effects of orange juice (OJ) supplemented with vitamin D3 (2000 IU) and probiotics (Lacticaseibacillus casei Shirota and Lacticaseibacillus rhamnosus GG, 10⁸ cfu/mL) on cardiometabolic risk factors in overweight and obese adults following a Westernized-type diet. Fifty-three high-risk individuals were randomly assigned to one of two groups. Over 8 weeks, one group consumed a vitamin D3 and probiotic-enriched OJ and the other regular OJ (control). Diets remained unchanged and were documented through food diaries. Measures of metabolic and inflammatory markers and blood pressure were measured at the start and end of the study. Post-intervention, the enriched OJ group showed the following significant metabolic improvements (without changes in triglycerides, inflammation, or central blood pressure): reduced fasting insulin, peripheral blood pressure, body weight (−1.4 kg 95% CI: −2.4, −0.4), energy (−270 kcal 95% CI: −553.2, −13.7), macronutrient (dietary fat −238 kcal 95% CI: −11.9, −1.0; carbohydrates −155 kcal 95% CI: −282.4, −27.3; sugars −16.1 g 95% CI: −11.9, −1.0) intake, and better lipid profiles (total cholesterol −10.3 mg/dL 95% CI: −21.4, 0.9; LDL-C −7 mg/dL 95% CI: −13.5, −0.5). The enriched OJ led to weight loss, less energy/macronutrient consumption, improved lipid profiles, and increased insulin sensitivity after 8 weeks in those following a Westernized diet, thus indicating potential benefits for cardiometabolic risk. This study was a part of FunJuice-T2EDK-01922, which was funded by the EU Regional Development Fund and Greek National Resources.

This study aimed to determine the glycemic index (GI) of a commercial mixed fruit juice (apple, orange, grape, and pomegranate; FJ) fortified with vitamin D3 or n-3 polyunsaturated fatty acids (PUFA) or probiotics, and their combination, and their effects on glycemic responses and salivary insulin concentrations. In a randomized controlled, double-blind, crossover study, 11 healthy participants (25 ± 2 years; five women; body mass index = 23 ± 1 kg/m²) were randomly assigned to receive five types of FJs [vitD (with vitamin D3); n-3 (with n-3 PUFA); probiotics (with Lacticaseibacillus casei Shirota and Lacticaseibacillus rhamnosus GG); vitD-n-3-probiotics FJ (combination of vitD3-n-3-probiotics), control (regular FJ)], all containing 50 g available carbohydrate, and glucose as reference drink. All FJs provided low GI values (control: 54; vitD3: 52; n-3: 51; probiotics: 50; and vitD-n-3-probiotics combination: 52, on glucose scale). Compared to the FJ control, the enriched FJs produced different postprandial glycemic and insulinemic responses and affected satiety scores. All FJ types, regardless of the added biofunctional ingredients, attenuated postprandial glycemic responses, which may offer advantages to glycemic control.

Introduction: The purpose of this study was to test the hypothesis that a preload including orange fruit juice (FJ) enriched with 50 μg of vitamin D3, 8.33 g of n-3 PUFA, and 108 cfu/mL of Lacticaseibacillus casei Shirota and Lacticaseibacillus rhamnosus GG probiotics, consumed as a snack before a meal, would (a) have greater short-term effects on satiety, as measured by the subsequent ad libitum meal intake, and (b) induce greater satiety, as assessed using visual analogue scales (VAS), in normal-weight and overweight healthy individuals compared to the same orange FJ without any fortification. Methods: Forty-six healthy individuals (normal weight: n = 24, 25 ± 1 years, BMI: 21 ± 1 kg/m²; overweight: n = 22, 28 ± 2 years, BMI: 27 ± 1 kg/m²) participated in this randomized, double-blind, within-subject crossover study. The participants consumed a standardized breakfast after 12 h of fasting. Two hours later, they were given 50 g of available carbohydrates from the two preloads (enriched orange FJ or control FJ) in random order, with a one-week washout period, and three hours later, they were offered an ad libitum lunch. The participants rated their hunger, desire to eat, perceived fullness, thirst, preoccupation with food, and pleasure of eating on visual analogue scales (VAS) at the baseline and at 15–30 min intervals up to 7 h of the intervention. Results: A statistical analysis of the results showed that when the individuals consumed the preload that included the FJ enriched with biofunctional ingredients, they had lower feeling of hunger, desire to eat, and preoccupation with food, and a higher perceived fullness at all time points between the preload and the meal. Additionally, the overweight individuals had a lower total energy intake at the meal and a lower energy intake 24 h post intervention day, as well as lower protein and fat intakes, compared to the normal-weight individuals. Discussion: Since the macronutrient contents of both preloads were similar, the satiating power of the enriched FJ indicates that the added ingredients (vitamin D3, n-3, and probiotics) have biofunctional properties that induce fullness and reduce the total energy intake, particularly in overweight individuals. The addition of enriched FJ to a snack seems to promote satiety besides providing valuable nutrients, and it may be an effective strategy for body weight control.

Introduction: The health benefits of eating fruits have been well established. Fruit juice is the product of the extraction or pressing of the natural liquid contained in fruits. The glycemic index (GI) is a tool developed to systematically classify carbohydrate-containing foods according to the time-integrated effects on postprandial glycemic responses. This study aimed to determine the effects of consuming a mixed commercial fruit juice (containing apples, oranges, grapes, and pomegranates) fortified either with two probiotic strains (Lacticaseibacillus casei Shirota and Lacticaseibacillus rhamnosus GG), or with vitamin D3, or with n-3 polyunsaturated fatty acids (PUFA), or with a combination of all of the aforementioned biofunctional ingredients versus the same control fruit juice without biofunctional ingredients on the postprandial glycemic and insulinemic responses. Methods: Eleven healthy, normal-weight volunteers (25—2 years; five females; BMI = 23 ± 1 kg/m²) participated in this randomized, double-blind, crossover clinical trial and were randomly assigned to receive five types of fruit juices (the fruit juice control, fruit juice with 50 μg vitamin D3, fruit juice with 8.33 g n-3 PUFA, fruit juice with 10⁸ cfu/mL probiotics, and fruit juice with vitamin D3, n-3 PUFA, and probiotics, all tested once) and D-glucose as a reference drink, which was tested two times. They all contained 50 g available carbohydrates, and the fruit juices were administered at different weeks in a random sequence according to the recommended glycemic index methodology. Capillary blood glucose and salivary insulin samples were collected at the baseline and for 180 min post consumption. Results: All the fruit juices provided low GI values (control: 54; vitamin D3: 52; n-3: 51; probiotics: 50; vitamin D3-n-3 PUFA-probiotics combination: 52, on the glucose scale). All the fruit juice types provided lower peak glucose values, smaller mean glycemic and insulinemic responses, and were more pleasurable than glucose was. Discussion: All the fruit juice types, regardless of the added biofunctional ingredients, attenuated the postprandial glycemic responses, which may offer advantages for glycemic control.

Introduction: Mixed fruit juices (FJ) may have several benefits on subjective appetite. They may curb hunger and provide sustained energy throughout the day. This study aimed to determine the effects of consuming a mixed commercial FJ (apple, orange, grape, pomegranate; FJ-control) and the same FJ fortified either with 2 probiotics strains (108 cfu/mL Lacticaseibacillus casei Shirota and Lacticaseibacillus rhamnosus GG), 50 μg vitamin D3, 8.33 g n-3 polyunsaturated fatty acids, or with the combination of all of these biofunctional ingredients (vitamin-D3-n-3-probiotics), on subjective appetite and blood pressure (BP). Methods: Clinically healthy volunteers participated in this randomized, double-blind, crossover, controlled trial. In total, 11 healthy and normotensive volunteers (25 ± 2 years; 6 males; BMI = 23 ± 1 kg/m²) were randomly assigned to receive the 5 types of FJs, all containing 50 g available carbohydrates. Participants rated their hunger, desire to eat, perceived fullness, thirst, preoccupation with food, and pleasure of eating on visual analog scales (VAS) at baseline and up to 180 min after consumption of each test FJ. BP was measured at the beginning and end of each drink test session. Results: The FJ with vitamin-D3 significantly increased hunger compared with the FJ-control. The FJ with vitamin-D3 significantly increased desire for food compared to the FJ with n-3, FJ combination, and FJ-control. The FJ with n-3 significantly increased fullness compared to the FJ with vitamin-D3 and the FJ with probiotics. The FJ with vitamin D3 significantly increased thirst compared to the FJ combination, n-3, probiotics, and FJ-control. All FJs were pleasurable. The FJ with vitamin-D3 and n-3 significantly increased systolic BP compared to the other FJs, without differences between the other FJs. The FJ with vitamin-D3 significantly increased diastolic BP, without differences between the other FJs. Discussion: FJs affected subjective satiety and BP acutely. Consumption of the FJ with vitamin-D3 increased systolic and diastolic BP, hunger, desire to eat, and thirst acutely; whereas consumption of the FJ with n-3 increased systolic BP and fullness acutely. All these effects were observed when these biofunctional ingredients were consumed alone, but not when ingested in combination (FJ with vitamin-D3, n-3, and probiotics), which needs to be further investigated.