The Effect of Cold Press Juice Consumption During Snack Time on Hunger Level and Food Intake Based on Visual Analogue Scale (VAS)

Obesity is a chronic disease linked to excessive unhealthy snacking and sedentary behaviour. In attempts to combat obesity, increasing fruits and vegetables consumption has been recommended. To date, no study has evaluated the effectiveness of cold pressed juice (CPJ) on obesity. This study aimed to evaluate the effect of CPJ on hunger level and food intake in adults using the visual analogue scale (VAS). Fifty-one adult participants (25.80 ± 7.92 years old) were divided into normal (NO) and overweight/obese (OW/OB) groups and they consumed CPJ and non-CPJ during the snacking time. After the standardized breakfast, hunger levels were measured with VAS every 30 minutes for 5 hours. Participants had an ad libitum lunch and food intake was measured. Findings indicate that CPJ reduced the desire to eat fatty foods in OW/OB subjects at +180, +240, and +270 minutes (p-value<0.05). CPJ was less effective in regulating hunger, satiety, and the desire to eat sweet and salty foods in both BMI groups (p-value>0.05). Moreover, CPJ did not significantly suppress food intake in NO and OW/OB subjects. These findings serve as a preliminary step in exploring obesity management targeting hunger level suppression and food intake reduction.


Introduction
The WHO has declared obesity to be a global epidemic, as it has affected 650 million adults in the global population.In the past four decades, the prevalence of obesity has increased by more than 9% in both men and women [1].The Indonesian national health survey conducted in 2018 also shows a high prevalence of obesity, reaching 23.1% of its total population [2].This condition has often been associated with various non-communicable diseases, such as hypertension, type-2 diabetes, etc. [3,4].The highest contributor to obesity lies in the imbalance of energy input from caloric intake with the energy expended from the body from physical activity [5,6].Its development may be due to unhealthy snacking habits, especially eating processed foods containing excessive amounts of saturated fat, sugar, and sodium, as well as sedentary behaviour [7].
Increasing fibre-containing fruit and vegetable intake has been recommended as a crucial way to prevent obesity since its consumption is linked to reduced chronic disease risks, improved digestion, reduced hunger, and weight loss [8,9,10,11].A study reported by Wien et al. [12] using crossover repeated measurement also shows that consuming apples before a meal does increase satiety levels and fullness.Subjects who consumed vegetables along with their meal also experienced a lengthened feeling of fullness for three hours [13].Consuming cold pressed juice (CPJ) is a more practical way of incorporating more fruits and vegetables into diets [14].A study by Eckert-Krause [15] showed that fruit juice consumption can cause weight reduction due to its low calories.Another study by Yu et al. [16] showed that the consumption of fruit or vegetable juice was able to attenuate energy intake and aid in weight management.To date, many studies have reported the benefits of fruits and vegetables (both in whole or as juice) suitable for weight management and appetite regulation.However, despite the abundant research, there has not been any study that specifically assessed the effect of CPJ made from a mixture of fruits and vegetables on obesity management based on the subjects' hunger level measurement and food intake.
Obesity prevalence has been rapidly increasing worldwide and poses a threat for the global population's health and well-being [17].Therefore, this study aims to evaluate the effect of CPJ made from fruits and vegetables on hunger levels and food intake in adults using the virtual analogue scale (VAS) assessment in an attempt for obesity management.The subjects were divided into normal (NO) and overweight/obese (OW/OB) body mass index (BMI) to evaluate the effect of CPJ on the different BMI groups.This study was also aimed to fill the gap of the Sustainable Development Goal (SDG) regarding healthy life and well-being [18] to improve fruit and vegetables consumption.

Sample preparation
The CPJ used in this study consisted of 32 % apple, 24 % spinach, 24 % pineapple, 20 % coconut water, and 1 % lemon.The raw materials were weighed before being processed accordingly.Spinach was washed, dried, cut into pieces, and cold pressed.Meanwhile, apples were washed, cut into pieces, deseeded, soaked in salt water for 10 minutes, and cold pressed.Coconut water was pasteurized at 72 o C for 15 minutes and added to the juice.Pineapples are deskinned, washed with water, cut into slices, and cold pressed.Lemons are washed, sliced into half, and squeezed.All the extracted ingredients were then filtered, measured separately, and combined in a sterilized container.The CPJ was then stirred until homogenous, measured to one serving size (250 mL) and filled in a PET bottle.In comparison, the noncold pressed juice (NCPJ) was used as a control in this study.The NCPJ was a commercial fruit and vegetable juice (apple, mango, broccoli, kiwi, lemongrass) that was available in the market.The NCPJ mostly composed of water, sugar, fruit concentrates, and food additives (colorants, stabilizers).The major difference between CPJ and NCPJ was based on fibre content and ingredients.CPJ consists of 100% cold pressed fruits and vegetables with fibre content of 2.92 g, based on total dietary fibre analysis.Meanwhile, the commercially available NCPJ contains 0 g of dietary fibre, based on information stated on the product label.All the sample preparations were conducted in PT Pharos Indonesia, Jakarta.

Subject recruitment
Fifty-one healthy subjects aged 18-55 years old were recruited for this study (mean age 25.80 ± 7.92 years old).Subjects were recruited in PT Pharos Indonesia, Jakarta.Several inclusion criteria for subject selection included having BMI above 18.5 kg/m 2 and no allergies.Subjects with BMI between 18.5 to 24.9 kg/m 2 were categorized as NO, while subjects with BMI above 25 kg/m 2 were categorized as OW/OB groups.Subjects were also required to fill in a screening questionnaire consisting of questions about their personal information (gender, age, occupation), their general medical history, eating patterns, and lifestyle habits [19].Additionally, subjects were excluded if they had a medical condition that required them to take medicine that could influence their appetite, nutrition absorption, body mass, and/or mood.In addition, subjects who were having or conducting a low-calorie diet for the previous two months were also excluded [20].Subjects that have agreed to participate in this study were asked to provide their consent by signing the informed consent form at the beginning of the evaluation [21].All the participation were based on voluntary and followed the declaration of Helsinki of using human subjects.

The test procedure
The test was conducted as a cross-sectional study.Before the test, subjects were instructed to fast from 23.00 on the previous day (they were only allowed to consume water and non-caloric beverages during fasting time).Then, during the evaluation day, the subjects were handed a standardized breakfast (408 kcal) which consisted of whole wheat bread (Sari Roti, 2 slices/70 g), cheese (Kraft Singles, 1 slice/17 g), chicken slice (Fiesta, 30 g), boiled egg (medium-sized/50-60 g), tomato sauce (Del Monte, 10 mL), and water (Cleo, 220 mL) [20].This breakfast was provided at 08.00 and the participant have to consume the breakfast directly in front of the evaluators.The total energy and nutritional composition of the breakfast meal are presented in Table 1.Both CPJ and NCPJ were presented to subjects at 10.00 or during snack time and the subjects were instructed to consume the CPJ or NCPJ directly.During the evaluation, subjects were only allowed to drink water moderately.Ad libitum lunch was provided at 14.00.The subjects were served a buffet-like setting consisting of spaghetti and Bolognese sauce as the menu and they could freely take the amount of food on their plates (Table 2 present the nutritional composition per portion).The lunch was weighed, and the food left on the plate was also weighed [19] in order to calculate the exact amount of the food consumed by the subject.The food consumed by each participant was then calculated to measure their total lunch (calories, protein, carbohydrate, and fat) intake.The VAS was used to assess the subjects' hunger level and desire to eat specific foods [22].Originally, this measurement tool consists of 8 questions assessing hunger, satiety, fullness, desire for food, as well as the desire to eat sweet, salty, savoury, and fatty foods [23].The subjects' hunger level was measured within a 30-minute interval at 11-time points, starting from 0 minutes (30 minutes before snacking) at 09.30 until 14.30 (+300 minutes) or 30 minutes after lunch [19] Subjects were required to fill out the scale by marking the interval between 0 to10 cm according to their condition.The anchored two ends of the line state the two opposing statements answering a specific question (Table 3).

Data analysis
The f-test was used as the preliminary statistical test to analyse equal variance between two samples [24].The t-test was performed to analyse the difference between the effects of (1) CPJ and NCPJ in NO subjects, (2) CPJ and NCPJ in OW/OB subjects, and (3) CPJ in NO and OW/OB subjects.The statistical analysis was calculated using a 95 % confidence interval [11].Similarly, both f-test and t-test were performed to analyse equal variance between samples.The initial measurements of food taken during lunch are first converted into kilocalories of total energy (kcal), carbohydrates (g), protein (g), and fat (g).The data is then tabulated and analysed using IBM SPSS Statistic version 25 with a confidence interval of 95 %.

The effect of cold press juice on hunger levels
NO subjects who were given CPJ initially had higher hunger levels compared to the control group (Figure 1a).The control group started to experience increased hunger levels at minute 120 compared to the CPJ group.This trend was observed in both groups until lunch (14.00).Similarly, subjects in the OW/OB group have also experienced an increase in hunger levels over time.However, it was observed that OW/OB subjects who consumed CPJ had a lower hunger level compared to the control group (Figure 1b).However, there were no significant differences at a confidence interval of 95% for both BMI groups [25].The reduction in hunger levels may be reduced by the fibre content in CPJ [26].
Previous studies have discussed the benefits of dietary fibre in fruits and vegetables for appetite control through blood glucose stabilization and hormone-induced pathways [5,21].The result shows that CPJ did not have a satiating effect on NO subjects.Over the time, NO subjects experienced a decline in satiety after consumption of CPJ and NCPJ (Figure 2a).This may be due to the sensory properties of the CPJ in liquid-like form (beverages).Low-viscosity liquids are digested too quick; therefore, they may not transmit proper stimulation signals to indicate that food is consumed and form a feeling of satiation [27].In OW/OB subjects, CPJ was able to increase satiety for 30 minutes (Figure 2b).There was a decrease in satiety afterwards.However, based on the statistical results, there were no significant differences between the consumption of CPJ and NCPJ in NO and OW/OB subjects.
(a) (b) Figure 2. VAS results for satiety in (a) NO and (b) OW/OB subjects Snacks and lunch were presented to subjects at +30 and +270 minutes, respectively.
VAS results for the NO subjects regarding the desire to eat sweet foods showed that there were no significant differences between those who were treated with CPJ and NCPJ (Figure 3a).At 60 minutes, subjects who were treated with NCPJ had a lower desire to eat sweet foods.This may be attributed to the high sugar content (25 g) accumulated in 250 mL or one serving of NCPJ.Based on existing studies, the desire to eat foods may be reduced after craving needs have been met by consumption [28].Interestingly, OW/OB subjects showed a conflicting response (Figure 3b).The OW/OB subjects who consumed CPJ had a lower desire to eat sweet foods.The trend for the desire to eat sweet foods was much lower compared to the subjects who consumed NCPJ.Although statistical results were not significantly different, but the trend consistently showed similar results over time.The desire to eat foods can be influenced by multidimensional factors occurring in each individual during hunger level testing, such as differences in cognitive, emotional, behavioural, and physiological conditions [29].Subjects in the NO group showed an increase in the desire to eat salty foods over time (Figure 4).However, there was a trend of lowering the desire to eat salty foods when subjects consumed CPJ.During the process of sample preparation, an ingredient in CPJ was soaked in a salt solution to reduce browning.Soaking in salt water can cause the ingredient to absorb some of the salt content and make it saltier than NCPJ.Hence, subjects' desire to eat salty foods may be reduced [28].Upon comparison, CPJ consumption did not have a significant effect (p-value > 0.05) on hunger, satiety, and the desire to eat sweet foods of NO and OW/OB subjects.Both BMI groups experienced an increased hunger level, reduced satiety, and increased desire to eat sweet foods until lunchtime (14.00).Previous studies show that liquid or low-viscosity foods, like the CPJ, typically are consumed in a shorter time compared to solid or semi-solid foods.A shorter consumption time or sensory process will result in inadequate time for the body to generate an anticipative physiological response, such as salivation during the cephalic phase or hormone-inducing peptides during digestion [27].This condition will then influence satiety level.These results also corroborate a previous study reported by Tack et al. [30] stating that satiety and hunger are regulated to adjust the body's nutritional needs.Therefore, satiety levels in subjects will still decrease over time as the hunger levels increase.The insignificant difference between the consumption of CPJ and NCPJ may also be due to the low fibre content of CPJ (2.92 g).The fibre amount considered as relatively low compared to the recommended adequate intake (AI) for adult females (25 g) and males (38 g) daily [31], which this amount is required to promote health benefits [32].
Based on Figure 5a, NO subjects who consumed CPJ had a lower desire to eat fatty foods compared to subjects who consumed the control.The trend observed in the CPJ group remained stable until 270 minutes.Statistically, both intakes did not have a significant effect on the desire to eat fatty foods.However, CPJ was the better choice for subduing the desire of NO subjects to eat fatty foods (Figure 5b).Interestingly, the same trend was also observed in the OW/OB group.The CPJ was significantly better at controlling subjects' desire to eat fatty foods at 180, 240, and 270 minutes, compared to NCPJ.This may be due to the dietary fibre in CPJ as there was 0 fibre from NCPJ.Therefore, this ability may be contributed by fibre content in CPJ that can suppress desire to eat [26].When treated with CPJ, the OW/OB group tended to have a lower desire to eat fatty foods than the NO group (Figure 6).A significant difference was observed at 180, 240, and 270 minutes which indicates that CPJ may be able to subjugate the desire to eat fatty foods in OW/OB subjects longer.This noteworthy finding appears to contradict previous studies stating that subjects with higher BMIs tend to have more uncontrolled cravings when approaching meals [33].Any discrepancy with previous studies can be due to various internal or external factors of subjects during hunger level testing, including psychological conditions, food preferences, and hormones that may influence the observation [34].
Figure 6.VAS result for a desire to eat fatty foods in NO and OW/OB subjects with CPJ consumption Snacks and lunch were presented to subjects at +30 and +270 minutes, respectively.

The association between cold press juice consumption and food intake
Table 5 demonstrated the food intake during lunch, comparing CPJ and NCPJ groups across different BMI.There was no significant difference across energy, fat, protein, and carbohydrate intake for the two groups in NO subjects.In comparison, there was also no significant difference found between CPJ and NCPJ in OW/OB subjects in terms of their food intake.In merged NO and OW/OB groups, CPJ wasn't able to significantly lower the subjects' food intake during lunch (p-value = 0.866).The ability of CPJ to control food intake has been reported to be dependent on internal and external factors that may influence an individual's eating habits [34,35].Thus, the CPJ may be unable to generate enough satiating hormones to reduce food intake [27].

Conclusion and recommendations
The CPJ was able to assist OW/OB subjects in reducing their desire to eat fatty foods in longer periods compared to NO subjects.However, it was not able to reduce hunger, increase satiety, and reduce the desire to eat sweet and salty foods regardless of BMI groups.Other than that, consumption of CPJ did not able to significantly lower food intake in NO and OW/OB subjects.There were several limitations presented in this study.First, we suggest involving more subjects in future studies to confirm the results and to improve the statistical power.Second, a longitudinal study design may provide more accurate data compared to a cross-sectional study since this method limits the data measurement based on subjects' conditions during the testing time.Third, it is suggested to investigate the effect of CPJ by measuring the biochemical parameters directly, such as blood glucose levels or hormone-related satiety, that are directly related to hunger levels compared to VAS

Figure 1 .
VAS results for hunger in (a) NO and (b) OW/OB subjects Snacks and lunch were presented to subjects at +30 and +270 minutes, respectively.

Figure 3 .
VAS results for desire to eat sweet foods in (a) NO and (b) OW/OB subjects Snacks and lunch were presented to subjects at +30 and +270 minutes, respectively.

Figure 4 .
VAS results for desire to eat salty foods in (a) NO and (b) OW/OB subjects Snacks and lunch were presented to subjects at +30 and +270 minutes, respectively.

Figure 5 .
VAS results for desire to eat fatty foods in (a) NO and (b) OW/OB subjects Snacks and lunch were presented to subjects at +30 and +270 minutes, respectively.

Table 1 .
Total energy and nutritional composition for standardized breakfast

Table 2 .
Total energy and nutritional composition for lunch (per 740 g)

Table 3 .
[22]questions and assessment indicator[22]Satiety Would you like to eat something sweet?↑ Desire to eat sweet foods ↓ Desire to eat sweet foods Would you like to eat something salty?
↑ Desire to eat salty foods ↓ Desire to eat salty foods Would you like to eat something fatty?↑ Desire to eat fatty foods ↓ Desire to eat fatty foods

Table 4 .
There were 31 subjects involved in the NO group (nCPJ= 16, nNCPJ= 15) and 20 subjects in the OW/OB group (nCPJ= 10, nNCPJ= 10).All the subjects have been selected and did not have any criteria of exclusion.The characteristics of the subjects are summarized in Table4.Subject characteristics (adults aged 18-55 years old, n = 51)

Table 5 .
Energy and nutrients intake in NO subjects, OW/OB subjects, and CPJ and NCPJ group