This study is designed to compare two types of snacks (almonds or a cereal-based snack), eaten between meals, on measures of appetite, including appetitive hormones, self-reported feelings of hunger and fullness, and food intake at a buffet meal or in the home environment. The investigators hypothesize that the acute responses of appetitive hormones to a meal challenge protocol will differ between almond and cereal-based snacks based on multivariate models of satiety that will be predictive of ad libitum food intake at a dinner meal as part of the meal challenge protocol. Further, the investigators will estimate if, under free-living conditions, self-selected and self-reported food intake will show appropriate energy compensation for the added calories of the snacks, and determine if one type of snack is superior to the other in this regard.
This study will use a randomized, parallel design that includes an almond snack intervention and a cereal-based snack intervention group. The almond intervention will be roasted, unsalted almonds at a level of 56 grams per day for 4 weeks. The cereal-based intervention will be isocaloric snacks provided in the form of a mixture of dry cereal, pretzels, and bread sticks for 4 weeks. A satiety test protocol will be done at the beginning and the end of the intervention period. Each test day will include measures of satiety responses to two standard meals, two snacks (either almonds or cereal-based snacks), and a dinner buffet. The protocol to evaluate satiety signals include tonic measures that may signal homeostasis to the brain and evaluation of episodic signals that may drive food intake In addition, other modulators of satiety will be tested including evaluation of preferences for palatable foods, self-reports of cravings and satiety using questionnaires, and perceived hunger, fullness, desire to eat.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
10
The almond intervention will be roasted, unsalted almonds provided at 56 g/day for 28 days. Almonds provide approximately 350 kcals/day.
The cereal-based intervention will be a prepared mix of cereal, pretzels, and bread sticks prepared at the WHNRC. It will be provided at the level of 350 kcals per day for 28 days.
USDA, ARS, Western Human Nutrition Research Center
Davis, California, United States
Baseline level and change in cholecystokinin
Cholecystokinin (CCK) measured in blood using an antibody based assay
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in peptide-YY
Peptide-YY (PYY) measured in blood using an antibody based assay
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in glucose-like peptide 1
Glucose-like peptide 1 (GLP-1) measured in blood using an antibody based assay
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in gastric inhibitory peptide
Gastric inhibitory peptide (GIP) measured in blood using an antibody based assay
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in insulin
Insulin measured in blood using an antibody based assay
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in glucose
Glucose measured by standard chemistry in blood
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in oleoylethanolamide
Oleoylethanolamide measured by mass spectrometry in blood
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in ghrelin
Ghrelin measured in blood using an antibody based assay
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in leptin
Leptin measured in blood using an antibody based assay
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in orexin
Orexin measured in blood using an antibody based assay
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, 90, 150, 180, 210, 240, and 270 minutes after a lunch meal
Baseline level and change in endocannabinoid profiles
Endocannabinoid profiles measured by mass spectrometry in blood
Time frame: Baseline, 60 minutes before lunch meal, and 10, 30, and 150 minutes after a lunch meal
Baseline level and change in hunger
Self-reported feelings of hunger measured on a visual analog scale. Responses will be a marked on an unsegmented line from 0 or "not at all" to 100 or "extremely."
Time frame: Baseline, every 30 minutes up to 480 minutes, and immediately before and after three meals
Baseline level and change in satiety
Self-reported feelings of fullness measured on a visual analog scale. Responses will be a marked on an unsegmented line from 0 or "not at all" to 100 or "extremely."
Time frame: Baseline, every 30 minutes up to 480 minutes, and immediately before and after three meals
Change in food intake at a dinner meal
Calories consumed at a dinner meal following the satiety protocol
Time frame: Week 1 and 4
Body composition reference measurement
Body composition (fat mass and fat-free mass in kg) will be measured once during the study using dual energy x-ray absorptiometry (DEXA)
Time frame: Week 1
Change in body weight
measured in kg
Time frame: Weeks 0, 1, 2, 3, and 4
Change in body fat
measured in kg using multi frequency bioimpedance
Time frame: Weeks 0, 1, 2, 3, and 4
Change in lean body mass
measured in kg using multi frequency bioimpedance
Time frame: Weeks 0, 1, 2, 3, and 4
Change in total body water
measured in kg using multi frequency bioimpedance
Time frame: Weeks 0, 1, 2, 3, and 4
Change in waist circumference
measured in cm
Time frame: Week 0 and 4
Change in hip circumference
measured in cm
Time frame: Week 0 and 4
Change in Food Choice
Food choice computer-based tests from Leeds, United Kingdom, will be used to estimate explicit liking and implicit wanting for several different categories of foods.
Time frame: Baseline and following a lunch meal at Weeks 0 and 4
Change in food craving
Food craving estimated from the questionnaire, Food Craving Inventory, on a 5 point likert scale
Time frame: Week 0 and 4
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Change in self-reported satiety
Self reported satiety measured using the 5-factor satiety questionnaire. Scale is a generalized labeled magnitude scale of 150 mm Subscales include mental hunger, physical hunger, mental fullness, physical fullness, and satiation. Subscale scores will range from 0 to 150.
Time frame: Week 0 and 4
Power of food questionnaire
Power of food questionnaire measured once on a 5 point likert scale
Time frame: Week 0
Food addiction questionnaire
Yale food addiction questionnaire measured once on a 5-point likert scale
Time frame: Week 0
Eating behavior
Dutch eating behavior questionnaire measured once. Scale is a 5-point likert scale. Sub scales include restrained eating, emotional eating, and external eating. Scores will be reported separately for each subscale.
Time frame: Week 0
Three factor eating inventory
Three factor eating inventory questionnaire measured once. Instrument has three subscales, combining likert scales and true/false questions. Subscales include cognitive restraint (score can range from 0 to 21), disinhibition (score can range from 0 to 16) and hunger (score can range from 0 to 14).
Time frame: Week 0
Premenstrual Syndrome
Premenstrual Syndrome screening questionnaire measured once. Scale is a 4-point likert. Subscales for premenstrual syndrome (PMS) or premenstrual dysphoric disorder (PMDD), reported separately.
Time frame: Week 0
General health and well-being
The SF-36 General Health and Well-being questionnaire measured once
Time frame: Week 0
Usual physical activity
Physical activity estimated from the Stanford Brief Physical Activity questionnaire. Scale is categorical for two subscales: work physical activity and leisure time activity.
Time frame: Week 0
Change in metabolic rate
Resting and post-prandial metabolic rate measured using indirect calorimetry.
Time frame: Baseline and 1 hour before lunch meal, 1 hour after lunch meal, and 1 hour after mid-afternoon snack
Change in dietary intake
Dietary intake estimated from 24-hour recall using a web based automated multi-pass method
Time frame: Ten dietary recalls collected at home during weeks 1-4
Genetic risk of obesity
A polygenic risk score (PRS) indexing genetic predisposition to obesity using known obesity single nucleotide polymorphisms (SNPs).
Time frame: Week 1
Change in liver fat
Liver fat assessed from the Controlled Attenuation Parameter (CAP) computed from the liver stiffness measurement using the Fibroscan®
Time frame: Week 0 and 4
Change in liver stiffness
Liver stiffness assessed from the shear wave speed with pulse echo ultrasound using the Fibroscan®
Time frame: Week 0 and 4