Ketosis and Appetite Suppression - What is the Maximum Carbohydrate Intake That is Still Associated With Appetite Suppression in a Low Energy Diet?
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 100
- 试验地点
- 1
- 主要终点
- Suppression of appetite indicated by appetite-related hormone Cholecystokinin (CCK)
研究概览
简要总结
Two dietary approaches, very low energy diets (VLEDs) and ketogenic low carbohydrate diets (KLCDs), have the ability to suppress appetite. The suppression of appetite typically observed during these diets is believed (but not clinically proven) to be due to ketosis, a condition where circulating concentrations of ketone bodies are increased due to a higher production of ketones in the liver. Little is known about the potential mechanisms through which ketosis may lead to appetite suppression in VLEDs and KLCDs. A 'ketogenic diet' typically contains less than 50 grams carbohydrate per day, yet ketosis has been seen in subjects who consume diets with a carbohydrates ranging between 59-192 grams per day. Although an association between ketosis and appetite suppression has been established, the minimum level of ketosis and maximum carbohydrate intake that is still associated with appetite suppression remains unknown and should be explored. The ability to increase carbohydrate intake while maintaining a suppressed appetite will allow dieters to consume more carbohydrate-rich food that is beneficial for health without feeling more hungry.
The study, 'can Appetite Suppression be achieved using KEtogenic Diets with more carbohydrates?' (ASKED) aimed to:
- to identify the maximum carbohydrate intake that is still associated with appetite suppression in a low energy diet and to determine the impact of a higher carbohydrate intake on appetite suppression, ketosis, body composition, and resting metabolic rate. A
- to evaluate the impact of weight loss while in and out of ketosis on markers of appetite (appetite related hormones and appetite sensations measured using visual analogue scales).
详细描述
A total of 101 healthy, weight stable (< 2 kg variation in BW within the last 3 months), adult (18-65 years old) individuals with obesity (body mass index [BMI] 30-45 kg/m2) who were not actively trying to lose weight were recruited through advertisements in Facebook, Twitter and the intranet of St. Olavs Hospital and the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway from May 2017 - August 2018.
Informed consent was obtained from all participants before enrollment in the study, and participants were allowed to withdraw at any time.
Study participants were randomized to one of three intervention arms: low, medium, or high CHO groups. Computer-generated randomization was performed using a block sampling (fixed block size) and stratification approach to account for the potential confounding factors of sex and BMI (< 35 and ≥ 35 kg/m2). (34, 35). Study participants were not made aware of which intervention arm they were allocated to until the end of the trial. All participants underwent an 8-week, supervised LED containing different amounts of CHO, followed by 4 weeks of gradual refeeding and weight stabilization. Measurements were taken before diet initiation (baseline), at the end of the WL phase (week 8) and at the end of the weight stabilization phase (week 12) to allow for the evaluation of the impact of WL in or out of ketosis on appetite markers.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •class I or II obesity (BMI 30-45 kg/m2)
- •weight stable (<2 kg variation in weight within the last 3 months)
- •not currently dieting to lose weight
- •women who are either post-menopausal, taking oral contraceptives or with a normal cycle (28 ± 2 days)
排除标准
- •breast-feeding
- •drug or alcohol abuse within the last two years
- •currently taking medication known to affect appetite or induce weight loss
- •enrolled in another obesity treatment program
- •history of psychological disorders
- •having had bariatric surgery
- •metabolic diseases (such as hypo/hyperthyroidism and diabetes type 1 or 2)
- •eating disorders
- •lactose intolerance
- •gastrointestinal (particularly cholelithiasis), kidney, liver, lung, cardiovascular disease
- •malignancies
结局指标
主要结局
Suppression of appetite indicated by appetite-related hormone Cholecystokinin (CCK)
时间窗: 12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period)
Measurement of plasma samples of appetite related hormone Cholecystokinin (CCK) measured in fasting, immediately after a meal and every 30 minutes for a period of 2.5 hours. Blood samples are first collected in Ethylenediaminetetraacetic acid (EDTA) tubes (72 milliliters in total inclusive of blood collected for analysis of hormones listed above) and centrifuged for 10 minutes at 18 degrees celsius with 3200 revolutions per minute (RPM). Plasma samples are then stored in -80 degree celsius freezer until they are sent to the University of Copenhagen to be analyzed by the research group of Professor Jens F Rehfeld using his 'In-house Radioimmunoassay method'. The results of plasma CCK will be presented in picomoles (pmol) per liter (l).
Suppression of appetite sensations measured using online visual analogue scales
时间窗: 12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period)
Assessed by an online version of Visual Analogue Scale (VAS), a validated scale used to measure appetite sensations in response to questions posed regarding feelings of hunger, fullness, desire to eat, prospective consumption. Study participants are asked questions such as 'How hungry do you feel right now?' and are asked to provide a response by marking across a 100 millimeter long line with sentences anchored at each end such as "I have never been more hungry/ or I am not hungry at all" corresponding to their feeling. VAS measurements are done in fasting, immediately after a meal and every 30 minutes for 2.5 hours. Measurements are quantified by measuring the distance from the left end of the line to the mark indicated by the participant.
Ketosis
时间窗: 12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period
Measured with beta hydroxybutyrate (BHB), a ketone body and indicator of ketosis in plasma form. Fasting blood samples are first collected in Ethylenediaminetetraacetic acid (EDTA) tubes (inclusive of the 72 milliliters of blood collected for analysis of appetite hormones listed above) and centrifuged for 10 minutes at 18 degrees celsius with 3200 revolutions per minute (RPM). Plasma samples are then stored in -80 degree celsius freezer until analysis using a Ketone Body Assay (MAK-134, Merck Millipore, USA). The results of plasma BHB will be presented in millimoles (mmol) per liter (l).
Suppression of appetite indicated by appetite-related hormones Active Ghrelin, Total Glucagon Like Peptide-1, Total Peptide YY and Insulin
时间窗: 12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period)
Measurement of plasma samples of appetite related hormones: Active ghrelin (AG), Total Glucagon Like Peptide-1 (Total GLP-1), Total Peptide YY (Total PYY) and Insulin measured in fasting, immediately after a meal and every 30 minutes for a period of 2.5 hours. Blood samples are first collected in Ethylenediaminetetraacetic acid (EDTA) tubes (72 milliliters in total) and centrifuged for 10 minutes at 18 degrees celsius with 3200 revolutions per minute (RPM). Plasma samples are then stored in -80 degree celsius freezer until analysis using a Metabolic Hormone Magnetic Bead Panel (Lincoplex Kit, Merck Millipore, USA). Results of plasma samples of these hormones will be presented in picograms (pg) per milliliter (ml).
次要结局
- Height(12 weeks (at start of study (Baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period))
- Body composition (air displacement plethysmography)(12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period))
- Percent fat/fat-free mass (air displacement plethysmography)(12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period))
- Body composition (bioelectrical impedance)(12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period))
- Waist and hip circumference(12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period))
- Body mass index (BMI)(12 weeks (at start of study (Baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period))
- Resting metabolic rate(12 weeks (at start of study (Baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period))
- Percent fat/fat-free mass (bioelectrical impedance analysis)(12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period))
- Intracellular and extracellular water measured using Bioelectrical impedance analysis(12 weeks (at start of study (baseline), at week 9 (after diet induced weight loss period), and week 13 (after weight stabilization period))