Changes in food cravings during low-calorie and very-low-calorie diets

Objective: This study examined food cravings during a primarily food‐based low‐calorie diet (LCD) and a supplement‐based very‐LCD (VLCD). Research Methods and Procedures: The Food Craving Inventory (FCI) was used to measure general cravings and cravings for specific types of foods (sweets, high fats, carbohydrates/starches, and fast food fats). The FCI was completed by participants in the LCD and VLCD programs at baseline and after 11 weeks of dieting. The VLCD group also completed the FCI at Week 6 and after 5 weeks of a refeeding phase, when their diet consisted primarily of solid food. Results: From baseline to Week 12, craving decreases were greater for the VLCD group than for the LCD group on all measures. All craving measures decreased significantly for the VLCD group. The LCD group experienced a marginally significant decrease in sweet cravings. Within the VLCD group, all craving measures decreased significantly by Week 6 and did not change thereafter, including after resumption of solid food intake, and craving scores during all dieting points were lower than baseline. Changes in cravings were not related to weight loss. Discussion: Cravings did not increase during either diet; all changes represented decreases. Compared with a primarily food‐based diet (LCD), a more restrictive supplement‐based diet (VLCD) resulted in significantly larger decreases in food cravings that occurred by the end of the 5th week of supplement use and did not rebound with resumption of solid food intake. The results of this study suggest that food cravings diminish with calorie restriction.     

The effects of a low-carbohydrate ketogenic diet and a low-fat diet on mood, hunger, and other self-reported symptoms

Objective: To investigate the effects of weight loss diets on mood, food cravings, and other self‐reported symptoms. Research Methods and Procedures: Mood and other symptoms were evaluated by participant self‐report using the Atkins Health Indicator Test (AHIT) in individuals undergoing weight loss following either a low‐carbohydrate, ketogenic diet (LCKD) or a low‐fat diet (LFD). Participants were 119 overweight community volunteers randomized to an LCKD or an LFD. An additional 51 participants who had completed an earlier trial contributed data for the psychometric analyses but were not included in the prospective analyses. Self‐reported symptom levels on seven scales factor‐analytically derived from the AHIT (negative affect, fatigue, somatic symptoms, physical effects of hunger, insomnia, hunger, and stomach problems) were acquired during 12 visits. Results: After adjusting for the change in BMI over the course of the trial, participants experienced significant improvements in most symptoms regardless of diet. Diet group × visit interactions were observed for negative affect [F(9,803) = 2.30, p = 0.015] and hunger [F(9,803) = 3.62, p < 0.0002]. Examination of means indicated that the LCKD group reported less negative affect and hunger, compared with the LFD group. Discussion: Regardless of diet, participants experienced significant improvement in a broad range of symptoms. Symptoms of negative affect and hunger improved to a greater degree in patients following an LCKD compared with those following an LFD. Whether these symptom changes explain the greater short‐term weight loss generally experienced by LCKD followers deserves further research.     

Influence of consumption of a high-protein vs. high-carbohydrate meal on the physiological cortisol and psychological mood response in men and women

Consumption of meals with different macronutrient contents, especially high in carbohydrates, may influence the stress-induced physiological and psychological response. The objective of this study was to investigate effects of consumption of a high-protein vs. high-carbohydrate meal on the physiological cortisol response and psychological mood response. Subjects (n = 38, 19 m/19f, age =25 ± 9 yrs, BMI = 25.0 ± 3.3 kg/m2) came to the university four times, fasted, for either condition: rest-protein, stress-protein, rest-carbohydrate, stress-carbohydrate (randomized cross-over design). Stress was induced by means of a psychological computer-test. The test-meal was either a high-protein meal (En% P/C/F 65/5/30) or a high-carbohydrate meal (En% P/C/F 6/64/30), both meals were matched for energy density (4 kJ/g) and daily energy requirements (30%). Per test-session salivary cortisol levels, appetite profile, mood state and level of anxiety were measured. High hunger, low satiety (81 ± 16, 12 ± 15 mm VAS) confirmed the fasted state. The stress condition was confirmed by increased feelings of depression, tension, anger, anxiety (AUC stress vs. rest p < 0.02). Consumption of the high-protein vs. high-carbohydrate meal did not affect feelings of depression, tension, anger, anxiety. Cortisol levels did not differ between the four test-sessions in men and women (AUC nmol·min/L p > 0.1). Consumption of the test-meals increased cortisol levels in men in all conditions (p < 0.01), and in women in the rest-protein and stress-protein condition (p < 0.03). Men showed higher cortisol levels than women (AUC nmol·min/L p < 0.0001). Consumption of meals with different macronutrient contents, i.e. high-protein vs. high-carbohydrate, does not influence the physiological and psychological response differentially. Men show a higher meal-induced salivary cortisol response compared with women.     

Similarities in Food Cravings and Mood States Between Obese Women and Women Who Smoke Tobacco

The present study assessed food cravings in a cohort of 229 women who differed in smoking history (i.e., never smoker, former smoker, and current smoker) and body weight (i.e., normal weight, overweight, and obese). Each subject completed the Food Craving Inventory (FCI), which measures cravings for sweets, high fats, carbohydrates/starches, and fast‐food fats, and the Profile of Mood States (POMS), which measures psychological distress. Smoking and obesity were independently associated with specific food cravings and mood states. Current smokers craved high fats more frequently than former and never smokers. They also craved starches more frequently and felt more depressed and angry than never smokers, but not former smokers. Whereas cravings for starchy foods and some mood states may be characteristic of women who are likely to smoke, more frequent cravings for fat among smokers is related to smoking per se. Similarly, obese women craved high fats more frequently than nonobese women and depression symptoms were intensified with increasing body weights. We hypothesize that the overlapping neuroendocrine alterations associated with obesity and smoking and the remarkable similarities in food cravings and mood states between women who smoke and women who are obese suggest that common biological mechanisms modulate cravings for fat in these women.     

Photoperiod regulates dietary preferences and energy metabolism in young developing Fischer 344 rats but not in same-age Wistar rats

The effects of photoperiod on dietary preference were examined using young growing Fischer 344 and Wistar rats, which are seasonal and nonseasonal breeders, respectively. Rats were provided a low-fat, high-carbohydrate diet (LFD: 66/10/24% energy as carbohydrate/fat/protein) and high-fat, low-carbohydrate diet (HFD: 21/55/24% energy as carbohydrate/fat/protein) simultaneously under long- (LD: 16 h light/day) and short-day (SD: 8 h light/day) conditions for 3 wk. Fischer 344 rats preferred the LFD to the HFD under the LD condition, whereas preference for both diets was equivalent under the SD condition. Consequently, their body weight and total energy intake exhibited 11-15 and 10-13% increases, respectively, under the LD condition. Calculation of energy intake from macronutrients revealed that rats under the LD condition consumed 20-24 and 9-13% higher energy of carbohydrates and proteins, respectively, than those under the SD condition. In contrast, Wistar rats preferred the LFD to the HFD irrespective of photoperiod and exhibited no photoperiodic changes in any parameters examined. Next, Fischer 344 rats were provided either the LFD or HFD for 3 wk under LD or SD conditions. Calorie intake was 10% higher in the rats fed the LFD than those fed the HFD under SD condition. However, rats under LD condition exhibited 5-10, 14, and 64% increases in body weight, epididymal fat mass, and plasma leptin levels, respectively, compared with those under the SD condition irrespective of dietary composition. In conclusion, photoperiod regulates feeding and energy metabolism in young growing Fischer 344 rats via the interactions with dietary macronutrient composition.     

Effects of fat, protein, and carbohydrate and protein load on appetite, plasma cholecystokinin, peptide YY, and ghrelin, and energy intake in lean and obese men

While protein is regarded as the most satiating macronutrient, many studies have employed test meals that had very high and unsustainable protein contents. Furthermore, the comparative responses between lean and obese subjects and the relationships between energy intake suppression and gut hormone release remain unclear. We evaluated the acute effects of meals with modest variations in 1) fat, protein, and carbohydrate content and 2) protein load on gastrointestinal hormones, appetite, and subsequent energy intake in lean and obese subjects. Sixteen lean and sixteen obese men were studied on four occasions. Following a standardized breakfast, they received for lunch: 1) high-fat (HF), 2) high-protein (HP), 3) high-carbohydrate/low-protein (HC/LP), or 4) adequate-protein (AP) isocaloric test meals. Hunger, fullness, and gut hormones were measured throughout, and at t = 180 min energy intake at a buffet meal was quantified. In lean subjects, hunger was less and fullness greater following HF, HP, and AP compared with HC/LP meals, and energy intake was less following HF and HP compared with HC meals (P < 0.05). In the obese subjects, hunger was less following HP compared with HF, HC/LP, and AP meals, and energy intake was less following HP and AP compared with HF and HC meals (P < 0.05). There were no major differences in hormone responses to the meals among subject groups, but the CCK and ghrelin responses to HP and AP were sustained in both groups. In conclusion, HP meals suppress energy intake in lean and obese subjects, an effect potentially mediated by CCK and ghrelin, while obese individuals appear to be less sensitive to the satiating effects of fat.     

Weight loss, diet composition and cardiovascular risk

PURPOSE OF REVIEW: Low-fat high-carbohydrate diets for weight loss have been challenged by alternative dietary approaches such as low-carbohydrate, high-protein or low glycaemic index. This review summarizes recent evidence on short-term metabolic effects and long-term adherence. RECENT FINDINGS: Very low carbohydrate freely fed diets containing less than 60 g carbohydrate per day appear more effective at inducing weight loss over 6 months than low-fat kilojoule-controlled diets although long-term compliance to both are equally poor. The LDL-cholesterol level did not increase in most studies and triglyceride levels fell dramatically in all studies, although none of the studies measured lipids in energy balance. Direct comparisons of the long-term efficacy and safety of low-fat and low-carbohydrate ad libitum diets are needed. High-protein diets with moderate levels of both fat and carbohydrate and diets low in glycaemic load are emerging dietary strategies, with medium-term benefits having been demonstrated in individuals with insulin resistance. Diets low in glycaemic index require larger studies to establish their efficacy for weight loss and cardiovascular disease risk reduction. SUMMARY: A variety of dietary approaches to achieve weight loss are consistent with metabolic improvements in cardiovascular risk in the short term. Long-term efficacy may depend on the intensity of education and frequency of follow-up more than the dietary composition per se.     

The internal circadian clock increases hunger and appetite in the evening independent of food intake and other behaviors

Objective:

Despite the extended overnight fast, paradoxically, people are typically not ravenous in the morning and breakfast is typically the smallest meal of the day. We assessed whether this paradox could be explained by an endogenous circadian influence on appetite with a morning trough, while controlling for sleep/wake and fasting/feeding effects.

Design and Methods:

Twelve healthy non‐obese adults (six males; age, 20‐42 years) were studied throughout a 13‐day laboratory protocol that balanced all behaviors, including eucaloric meals and sleep periods, evenly across the endogenous circadian cycle. Participants rated their appetite and food preferences by visual analog scales.

Results:

There was a large endogenous circadian rhythm in hunger, with the trough in the biological morning (8 AM) and peak in the biological evening (8 PM; peak‐to‐trough amplitude = 17%; P = 0.004). Similarly‐phased significant endogenous circadian rhythms were present in appetites for sweet, salty and starchy foods, fruits, meats/poultry, food overall, and for estimates of how much food participants could eat (amplitudes 14‐25%; all P < 0.05).

Conclusions:

In people who sleep at night, the intrinsic circadian evening peak in appetite may promote larger meals before the fasting period necessitated by sleep, whereas the circadian morning trough would theoretically facilitate the extended overnight fast. Furthermore, the circadian decline in hunger across the night would theoretically counteract the fasting‐induced hunger increase that could otherwise disrupt sleep.     

Insulin sensitivity, fat distribution, and adipocytokine response to different diets in lean and obese cats before and after weight loss

Obesity is a major health problem in cats and a risk factor for diabetes. It has been postulated that cats are always gluconeogenic and that the rise in obesity might be related to high dietary carbohydrates. We examined the effect of a high-carbohydrate/low-protein (HC) and a high-protein/low-carbohydrate (HP) diet on glucose and fat metabolism during euglycemic hyperinsulinemic clamp, adipocytokines, and fat distribution in 12 lean and 16 obese cats before and after weight loss. Feeding diet HP led to greater heat production in lean but not in obese cats. Regardless of diet, obese cats had markedly decreased glucose effectiveness and insulin resistance, but greater suppression of nonesterified fatty acids during the euglycemic hyperinsulinemic clamp was seen in obese cats on diet HC compared with lean cats on either diet or obese cats on diet HP. In contrast to humans, obese cats had abdominal fat equally distributed subcutaneously and intra-abdominally. Weight loss normalized insulin sensitivity; however, increased nonesterified fatty acid suppression was maintained and fat loss was less in cats on diet HC. Adiponectin was negatively and leptin positively correlated with fat mass. Lean cats and cats during weight loss, but not obese cats, adapted to the varying dietary carbohydrate/protein content with changes in substrate oxidation. We conclude that diet HP is beneficial through maintenance of normal insulin sensitivity of fat metabolism in obese cats, facilitating the loss of fat during weight loss, and increasing heat production in lean cats. These data also show that insulin sensitivity of glucose and fat metabolism can be differentially regulated in cats.     

Temporal changes in food preferences of wood mice (Apodemus sylvaticus L.)

Diet choice was determined for wild-caught wood mice (Apodemus sylvaticus L.), temporarily confined to cages in the field and offered a choice of 24–26 types of seeds and fruits in 2-h sessions throughout the night. The mice showed an overall preference for some foods over others. The set-up minimized influences on food preferences of predation risk, hunger, food availability and competition. Variation in food preferences was not attributable to differences between individuals, but followed a temporal pattern. The variety of foods eaten showed a bimodal pattern with peaks corresponding to the two most active periods at the beginning and end of the night. Both the amount of food eaten and variation in the amount diminished from the first to the second active period. An expected selection for carbohydrates early in the night and proteins at the end of the night was not found, but sugars were selected for early in the night. These results are discussed in relation to the conflict between an animal's continuous energy requirements and the essentially periodic activity of foraging.     

Food Aversions and Cravings during Pregnancy on Yasawa Island,Fiji

Women often experience novel food aversions and cravings during pregnancy. These appetite changes have been hypothesized to work alongside cultural strategies as adaptive responses to the challenges posed by pregnancy (e.g., maternal immune suppression). Here, we report a study that assessed whether data from an indigenous population in Fiji are consistent with the predictions of this hypothesis. We found that aversions focus predominantly on foods expected to exacerbate the challenges of pregnancy. Cravings focus on foods that provide calories and micronutrients while posing few threats to mothers and fetuses. We also found that women who experience aversions to specific foods are more likely to crave foods that meet nutritional needs similar to those provided by the aversive foods. These findings are in line with the predictions of the hypothesis. This adds further weight to the argument that appetite changes may function in parallel with cultural mechanisms to solve pregnancy challenges.     

Appetite and blood glucose profiles in humans after glycogen-depleting exercise.

Regulatory functions of glycogen stores and blood glucose on human appetite, particularly relating to exercise, are not fully understood. Ten men (age 20-31 yr) performed glycogen-depleting exercise in an evening, ate a low-carbohydrate dinner, and stayed overnight in the laboratory. The next day, blood glucose was monitored continuously for 517 +/- 23 (SE) min. Subjects had access to high-fat and high-carbohydrate foods after baseline glucose and respiratory quotient were determined. In the afternoon, 1 h of moderate exercise was performed. Baseline respiratory quotient was 0. 748 +/- 0.008, plasma free fatty acids were 677 +/- 123 micromol/l, insulin was 4.8 +/- 0.5 microU/ml, and leptin was 1.9 +/- 0.3 ng/ml. Postabsorptively, 8 of 10 meals were initiated during stability in blood glucose. Postprandially, the association between meal initiation and blood glucose declines became significant (chi(2) = 7. 82). During moderate exercise, blood glucose initially decreased but recovered before completion. When the glycogen buffer is depleted, meal initiation can occur during blood glucose stability; the relationship between blood glucose declines and meal initiation reestablishes with refeeding.     

A randomized cross-over study of the effects of macronutrient composition and meal frequency on GLP-1, ghrelin and energy expenditure in humans

ObjectiveLittle is known about human postprandial increase of energy expenditure and satiety-associated hormones in relation to both meal frequency and macronutrient composition.DesignRandomized cross-over study with four conditions for each participant.MethodsSeven men and seven women (mean age 23 ± 1.5 years) were randomly assigned to the order of intake of a 750 kcal drink with the same protein content while having either 20 energy-percent (E%) or 55 E% from carbohydrates and the remaining energy from fat. Participants were also randomized to consume the drinks as one large beverage or as five 150 kcal portions every 30 min, starting in the fasting state in the morning. Energy expenditure (EE) was determined every 30 min by indirect calorimetry. Hormonal responses and suppression of hunger (by visual-analogue scales) were also studied. A p < 0.013 was considered statistically significant following Bonferroni-correction.ResultsThe area under the curve (AUC) for EE was higher during the 2.5 h after the high-carbohydrate drinks (p = 0.005 by Wilcoxon) and also after ingesting one drink compared with five (p = 0.004). AUC for serum active GLP-1 was higher after single drinks compared with five beverages (p = 0.002). Although GLP-1 levels remained particularly high at the end of the test during the low-carbohydrate meals, the AUC did not differ compared with the high-carbohydrate occasions (low-carbohydrate: 58.9 ± 18 pg/ml/h, high-carbohydrate: 45.2 ± 16 pg/ml/h, p = 0.028). Hunger sensations were suppressed more after single beverages compared with five small drinks (p = 0.009).ConclusionsWe found higher EE during 2.5 h following one large drink compared with five smaller beverages. Since hunger was also suppressed more efficiently, and serum GLP-1 levels were higher after one compared with five smaller drinks, our findings do not support nibbling to avoid hunger or to keep up EE from morning to noon.     

Time of day type of food--relation to mood and hunger during 24 hours of constant conditions

A six-day high-carbohydrate meal (HC; 65 E% (energy percent) carbohydrates, 20 E% fat and 15 E% protein) and a six-day high-fat meal (HF; 40 E% carbohydrates, 45 E% fat and 15 E% protein) were given to seven healthy subjects in a crossover design. On the last day subjects were kept awake for 24 hours in a metabolic laboratory while substrate utilisation and energy expenditure were measured by indirect calorimetry. The subjects were given isocaloric meals every four hours. Results showed that hunger decreased at night (F = 4.2, p < 0.05) and linearly increased after meal intake. Macronutrient composition (fat/carbohydrates) seemed to be of less importance for hunger. Hunger and thirst were found to be strongly associated with gastrointestinal substances, for hunger the strongest being a negative correlation with triacylglycerol (partial correlation = -0.39). It is suggested that it might not be necessary for shift workers to eat full portions at night but that satiation will occur with less food. Possibly lack of adjustment of nocturnal food intake might be one reason why overweight is common in shift work populations.     

Contamination of food by crude oil affects food selection and growth performance,but not appetite,in an Arctic fish,the polar cod (Boreogadus saida)

The polar cod (Boreogadus saida) is recognized as a key species in Arctic marine food webs and it may, therefore, be important for the transfer of xenobiotics from lower trophic levels to its main predators, birds and sea mammals. The present work examines the effects of foods contaminated with 200 or 400 ppm crude oil on food selection patterns and appetite-growth relationships in polar cod using X-radiography. It is shown that sexually mature polar cod consumed mixtures of uncontaminated and oil-contaminated foods, and did not show a reduced overall appetite as compared with fish provided with uncontaminated food only. Food selection was, however, influenced by both sex and individual appetite. Male fish selected uncontaminated food when appetite was low, whereas females ingested contaminated and uncontaminated foods equally, irrespective of appetite level. The ingestion of oil-contaminated food led to a significant depression in growth performance in both male and female fish. Food contaminated with oil at a concentration of 500 ppm was completely rejected by both sexes.     

Food distance and its effect on nutrient balancing in a mobile insect herbivore

We investigated how the distance between foods of differing nutrient content affects macronutrient (protein and digestible carbohydrate) regulation and the patterns of food acquisition, movement and feeding activity in fifth-instar nymphs of Locusta migratoria (L.) (Orthoptera: Acrididae). We placed individual insects into one of three differently sized circular arenas (20, 40 or 80 cm diameter) that contained four dishes of chemically defined synthetic food. One of these dishes contained high-protein, low-carbohydrate food (P), and the other three dishes contained low-protein, high-carbohydrate food (C). Alone, these foods are nutritionally unbalanced, but together they are complementary. Regardless of arena size, locusts regulated their protein-carbohydrate intake to similar points, and in all three arenas they ate preferentially from the dish containing the P-food. We also recorded the patterns of foraging behaviour for 12 h on days 1 and 4 of the experiment, which allowed us to determine the effect of distance between foods and whether behaviour was modified with experience in the different arenas. Locusts' foraging behaviour in small arenas was similar on days 1 and 4, and the time they spent in different parts of the arena did not differ from that predicted by the simplest random probability model. In contrast, the foraging behaviour of locusts in the medium and large arenas changed between days 1 and 4, including spending more time in the area of the arena containing the P-food and visiting fewer of the C-food dishes. We discuss how distance between foods influences foraging strategies, and the possible role of learning in its development. Copyright 2003 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.      

Anthropometric and leptin changes in women following different dietary approaches to weight loss

Leptin may favorably respond to fat mass (FM) losses induced by a low-carbohydrate (LC) diet, although this is unclear. We examined serum leptin concentrations in women in midlife undergoing different dietary approaches to body weight (BW) loss. Women followed either a LC, high-protein (LCHP; n = 13) or high-carbohydrate, low-fat (HCLF; n = 12) diet for 12 weeks. Changes in anthropometric and soft-tissue mass measurements and leptin concentrations were assessed. Women in both diet groups had reductions in BW, BMI, fat-free soft-tissue mass, FM, body fat percentage, and central abdominal fat (CAF) (P < 0.001 for all variables) over the 12-week intervention. These changes were not significantly different between diet groups. Serum leptin concentrations decreased by 41.8% (P < 0.001) in the LCHP group and by 44.3% (P < 0.001) in the HCLF group from baseline to week 12, with no significant difference between groups. The association of CAF (r = 0.73) and FM (r = 0.83) change with leptin change was strong in the HCLF group. Leptin change did not relate to change in any variable in the LCHP group. Both LCHP and HCLF diets favorably lower FM, CAF, and leptin in women, suggesting that beneficial changes in leptin can be similarly achieved through different dietary approaches to BW loss.     

Short-term effects of a "health-at-every-size" approach on eating behaviors and appetite ratings

Objective: To assess the effects of a “Health‐At‐Every‐Size” (HAES) intervention on eating behaviors and appetite ratings in 144 premenopausal overweight women. Research Methods and Procedures: Women were randomly assigned to one of the 3 groups: HAES group, social support (SS) group, and control group (N = 48 in each group). Interventions were conducted over a 4‐month period, and measurements were taken before and after this period. Eating behaviors (cognitive dietary restraint, disinhibition, and susceptibility to hunger) were evaluated by the Three‐Factor Eating Questionnaire. Appetite ratings (desire to eat, hunger, fullness, and prospective food consumption) were assessed by visual analogue scales before and after a standardized breakfast. Results: More important decreases in susceptibility to hunger and external hunger were observed in the HAES group when compared with the SS group (p = 0.05, for susceptibility to hunger) and the control group (p = 0.02 and p = 0.005, for susceptibility to hunger and external hunger, respectively). In addition, women from the HAES group had more important decreases in postprandial area under the curve for desire to eat (p = 0.02) and hunger (p = 0.04) when compared with the control group. The change in the desire to eat noted in the HAES group was also different from the one observed in SS group (p = 0.02). Women from the HAES group experienced significant weight loss at 4 months (?1.6 ± 2.5 kg, p < 0.0001), which did not differ significantly from the SS and control groups (p = 0.09). An increase in flexible restraint was significantly related to a greater weight loss in both HAES and SS groups (r = ?0.39, p < 0.01; and r = ?0.37, p < 0.05, respectively). A decrease in habitual susceptibility to disinhibition was also associated with a greater weight loss in HAES and control groups (r = 0.31, p < 0.05; and r = 0.44, p < 0.05, respectively). Discussion: These results suggest that a HAES intervention could have significant effects on eating behaviors and appetite ratings in premenopausal overweight women, when compared with an SS intervention or a control group.     

Enriched protein diet-modified ghrelin expression and secretion in rats

Gastrointestinal (GI) integrity and function are regulated by nutrition and growth factors. The discovery of ghrelin, a natural growth hormone (GH) secretagogue produced by the gastrointestinal (GI) tract, is a potential link between diet and growth signals. The aim of this study was to evaluate macronutrient effect on ghrelin expression and secretion in addition to some possible function in intestinal trophic status. Wistar rats were fed a high-carbohydrate, high-protein (HP), high-fat or standard (St) diet. Animals received the same daily food volume and caloric intake. After 7 days, animals were fasted for 24 h and blood and tissue samples were obtained just before feeding or at 2 or 6 h after feeding. Fasting high-protein-fed rats had higher ghrelin plasma levels than with rats fed the high-carbohydrate, high-fat or standard diets. Two-hours after refeeding, ghrelin plasma levels had decreased in all groups with a slight recovery at 6 h after refeeding, except in the high-protein group. Ghrelin plasma levels in rats fed with the high-protein diet correlated negatively with their GH and insulin-like growth factor 1 (IGF-1) plasma concentrations which were also the lowest among the study groups. In conclusion, ghrelin secretion was nutritionally manipulated because a protein-enriched diet increased its levels.     

Development and Validation of the Food-Craving Inventory

Objective: The primary aim of this study was to develop and validate the Food-Craving Inventory (FCI), a self-report measure of specific food cravings. Research Methods and Procedures: In a preliminary study, participants (n = 474) completed the initial version of the FCI. The results from this study were used in developing the revised FCI. Participants (n = 379) completed the revised FCI in the primary study designed to develop a self-report measure of specific food cravings. Results: Common factor analysis yielded four conceptual factors (subscales) that were interpreted as high fats, sweets, carbohydrates/starches, and fast-food fats. Confirmatory factor analysis found that the four factors could be modeled as dimensions (or first-order factors) of a higher order construct—food craving. Test–retest and internal consistency analyses indicated good reliability for the total score and each of the subscales. Subscale scores were compared with scores on the Three Factor Eating Questionnaire and a conceptual measure of food craving. We found support for the content, concurrent, construct, and discriminant validity of the FCI. Discussion: The FCI was found to be a reliable and valid measure of general and specific food cravings. The FCI can be used in research related to overeating and binge eating. Also, it may be useful in treatment studies that target obesity and/or food cravings.