Study Title and Description
Coffee, hunger, and peptide YY.
Key Questions Addressed
|1||For [population], is caffeine intake above [exposure dose], compared to intakes [exposure dose] or less, associated with adverse effects on behavior*?|
Primary Publication Information
|Title||Coffee, hunger, and peptide YY.|
|Author||JA Greenberg,A Geliebter,|
Secondary Publication Information
There are currently no secondary publications defined for this study.
Extraction Form: Behavior - Design Details - INCLUDED Studies
No arms have been defined in this extraction form.
|Question... Follow Up||Answer||Follow-up Answer|
|What outcome is being evaluated in this paper?||Behavior|
|What is the objective of the study (as reported by the authors)?||Our objective was to assess the effects of caffeine, caffeinated coffee, and decaffeinated coffee, both alone and in combination with 75 g of glucose, on perceived hunger and satiety and related peptides.|
|Provide a general description of the methods as reported by the authors. Information should be extracted based on relevance to the SR (i.e., caffeine related methods)||We recruited 11 healthy male nonsmoker volunteers (mean age 6 standard deviation [SD] 23.5 6 5.7; mean height, 1.73 6 0.08 m; mean weight, 155.4 6 27.6 lb; mean body mass index [BMI] 23.6 6 4.2 kg/m2) who were not on any medications that could influence body weight or interfere with glucose metabolism. During the study period, volunteers were asked: (1) to keep diet, exercise, and alcohol intake stable; (2) not to consume caffeinated drinks such as coffee, tea, sodas, or sports drinks; caffeinated medications; caffeinated diet or energy supplements; or decaffeinated coffee; and (3) not to smoke. They were also asked not to use alcohol or perform exercise during the 48 hours prior to each laboratory visit. Next, each volunteer was given a randomly selected beverage: caffeinated coffee, decaffeinated coffee, caffeine in water, or water (placebo), and a second blood sample was drawn (t=0). All beverages were served at 110 degrees F–120 degrees F (43 degrees C–49 degrees C) and were ingested within 10 minutes. This procedure was similar to that used by Graham et al. , which yielded virtually identical circulating concentrations of methylxanthines for caffeinated coffee and caffeine in water. Based on a review of the literature, we used 6 mg of caffeine per kg body weight. This was equivalent to approximately 2 mugs of coffee (500–600 mL) for a 70-kg individual. For each volunteer, the volume of each beverage was the same at each visit and equal to the volume of caffeinated coffee required to deliver 6 mg of caffeine per kg of body weight. The beverage was always prepared in the same fashion, with 8 cups of water in the same drip-filter coffee machine (Chefmate, model #CMCM12W). Volunteers rested for 60 minutes after beverage ingestion and were then (t=60) asked to drink a 10-oz bottle of flavored water containing 75 g glucose (Fisher Scientific #TGP-401-223-PA). Blood samples were drawn at 60, 70, 90, 120, 150, and 180 minutes after ingestion of the initial beverage. Participants were required to rest for 5 minutes during each blood draw (total of 8 draws) during each visit. During each 5-minute rest period, participants were asked to rate their levels of hunger and satiety (fullness) on visual analog scales (VAS) . The scales ranged from 0 to 100. To assess hunger, the participants were asked ‘‘how hungry do you feel?’’ A rating of 0 indicated ‘‘I am not hungry at all’’ and 100 corresponded to ‘‘I have never been more hungry.’’ For satiety, the subjects were asked ‘‘How satisfied do you feel?’’ A rating of 0 corresponded to ‘‘I am completely empty’’ and 100 corresponded to ‘‘I cannot eat another bite.’’|
|How many outcome-specific endpoints are evaluated?||1|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||hunger|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|What is the study design?||Controlled Trial|
|Randomized or Non-Randomized?||RCT|
|What were the diagnostics or methods used to measure the outcome?||Subjective|
|Optional: Name of Method or short description||visual analog scale (VAS)|
|Caffeine (general)||Caffeine (general)|
|What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.)||placebo (0 mg caffeine) to 6 mg/kg caffeine in water|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||N/A|
|Provide a general description of results (as reported by the authors).||Hunger AUC was not significantly different for caffeine than placebo or for decaffeinated coffee vs caffeinated coffee.|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||No|
|What were the authors's observations re: trend analysis?|
|What were the author's conclusions?||The decreases in hunger and increases in PYY after consumption of decaffeinated coffee did not appear after consumption of caffeinated water. In conclusion, this randomized clinical trial found that ingestion of decaffeinated coffee acutely decreased hunger and increased plasma PYY. Caffeine did not exhibit this effect.|
|What were the sources of funding?||This project was conducted with funds from the Professional Staff Congress - City University of New York (PSCCUNY) Research Award Program, Award # 68431-00 37.|
|What conflicts of interest were reported?||Financial conflicts of interest: None.|
|Does the exposure (dose) need to be standardized to the SR?||Multiple metrics|
|Provide calculations/conversions for the exposure based on the decision tree in the guide (for all endpoints/exposure levels of interest).||Average weight of participants = 155 lb = 70 kg 6 mg/kg * 70 = 420 mg|
|List all the endpoint(s) followed by the dose (mg) which will be used in comparison to Nawrot. Characterize value as LOAEL/NOAEL, etc. if possible.||hunger - NOAEL = 420 mg|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||No effects seen at levels above Nawrot|
|What is the importance of the study with respect to the adverseness of the outcome?||Low|
No baseline characteristics have been defined for this extraction form.
Results & Comparisons
No Results found.
|Arm or Total||Title||Description||Comments|
No quality dimensions were specified.
No quality rating data was found.