Very Low Calorie Diet for Obesity

(SAFETY Trial)

Overseen By Devika Umashanker, MD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Hartford Hospital

Must not be taking: Weight loss medications

Disqualifiers: Lactose intolerance, Type 1 diabetes, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 12

Duration: 12 weeks

30 Participants Needed

Trial Summary

Do I have to stop taking my current medications for the trial?

The trial protocol does not specify whether you need to stop taking your current medications. However, if you are on FDA-approved weight loss medications, you cannot participate in the trial.

What data supports the effectiveness of the treatment Very Low Calorie Diet for obesity?

Very low calorie diets can lead to rapid weight loss and improvements in obesity-related health issues like high blood pressure and type 2 diabetes. However, maintaining weight loss long-term often requires additional lifestyle changes. ^{1 2 3 4 5}

Is a Very Low Calorie Diet safe for treating obesity?

Very Low Calorie Diets (VLCDs) appear to be safe for treating obesity when used for up to 3 months under careful medical supervision, with no diet-related deaths reported in over 10,000 cases. However, earlier versions of these diets, like 'liquid protein' diets, were linked to at least 60 deaths, highlighting the importance of using high-quality protein and medical oversight. ^{4 6 7 8 9}

How does the Very Low Calorie Diet treatment for obesity differ from other treatments?

The Very Low Calorie Diet (VLCD) is unique because it involves consuming a significantly reduced number of calories, typically between 400 and 800 calories per day, leading to rapid weight loss. Unlike other diets that focus on macronutrient composition, VLCDs emphasize severe calorie restriction and require careful medical supervision due to the risk of severe complications. ^{1 2 3 10 11}

What is the purpose of this trial?

Class 4 obesity is defined as a BMI ≥50Kg/m2, representing approximately ≥150 pounds of excess weight. For patients with Class 4 obesity, metabolic and bariatric surgery (MBS) is the only effective treatment. However, MBS is associated with a higher rate of perioperative morbidity and mortality for patients with Class 4 obesity. Additionally, more patients with Class 4 obesity experience suboptimal weight loss. For patients with Class 4 obesity, preoperative weight loss can reduce the technical difficulty of surgical procedures, rendering MBS safer. Preoperative weight loss may also decrease visceral adipose tissue and liver volume as well as reduce weight-related comorbidities. A very low-calorie diet (VLCD), which involves restricting caloric intake to approximately 800 kcal/day, is one strategy to help patients achieve weight loss preoperatively. Although studies show that a VLCD prior to MBS yields weight loss, reduces liver volume and rates of perioperative complications, most preoperative VLCDs are short (2-8 weeks) with variable adherence. To date, no study has systematically assessed the feasibility and acceptability of a standard 12-week VLCD among patients with BMI ≥50 pursuing MBS. No study has evaluated postoperative weight loss among patients who have undergone a preoperative VLCD. This study will be a single arm trial designed to test the feasibility, acceptability, and preliminary efficacy of a 12-week VLCD program prior to sleeve gastrectomy (SG) and associated weight loss up to 1 year following MBS. The investigators will enroll 24 patients aged 18-70, with a BMI≥50Kg/m2, and are approved for SG. Participants will consume up to 5 meal replacement protein shakes and 2 cups of vegetables daily for 12 weeks. Participants will attend weekly in-person office visits with the clinicians at the Hartford Hospital Medical and Surgical Weight Loss Center in Glastonbury, CT to assess weight loss, physical and mental health, feasibility and acceptability of and adherence to the VLCD. The investigators hypothesize that a 12-week VLCD is feasible in this population, defined as ≥70% (18 out of 24 participants) completing the program. The investigators hypothesize that better attendance at the weekly visits and higher adherence to the diet recommendations will provide greater weight loss preoperatively and percent total weight loss at the completion of VLCD, on the day of MBS, and at 3, 6, and 12 months post-surgery. Findings from this study may lead to additional projects that aim to develop and implement an optimal pre-surgery and post-surgery clinical care model for bariatric patients.

Eligibility Criteria

This trial is for adults aged 18-70 with Class 4 obesity (BMI ≥50Kg/m2) who are approved for sleeve gastrectomy. It aims to see if a strict diet of about 800 calories per day, using protein shakes and vegetables for 12 weeks before surgery, can make the operation safer and improve weight loss outcomes.

Inclusion Criteria

BMI greater than or equal to 50 kg/m2

I am approved for sleeve gastrectomy as my main weight loss surgery.

Able and willing to sign an Informed Consent document

Exclusion Criteria

I am currently taking FDA-approved weight loss medications.

Are lactose intolerant

I have been diagnosed with Type 1 diabetes.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants follow a 12-week very low-calorie diet (VLCD) program with weekly in-person visits to assess weight loss, physical and mental health, and adherence to the diet

12 weeks

12 visits (in-person)

Follow-up

Participants are monitored for weight loss and health outcomes at 3, 6, and 12 months post-surgery

12 months

Treatment Details

Interventions

• Very Low Calorie Diet

Trial Overview The study tests a preoperative very low-calorie diet's feasibility and effectiveness in patients with severe obesity undergoing sleeve gastrectomy. Participants will follow this diet strictly for three months, attending weekly check-ups to monitor their progress.

Participant Groups

Group I: Very Low Calorie Diet Experimental Treatment 1 Intervention

Very Low Calorie Diet - caloric intake restricted to approximately 800 kcal/day

Who Is Running the Clinical Trial?

Hartford Hospital

Lead Sponsor

Trials

140

Recruited

19,700+

Findings from Research

In a 90-week study involving five seriously overweight individuals, a self-help group model combined with a very-low-calorie diet led to significant and sustained weight loss, with four participants continuing to lose between 33.7 and 66.8 kg.

All subjects maintained a weight well below their starting point, suggesting that this approach may be effective for long-term obesity management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Long-term outcome of a self-help very-low-calorie-diet weight-loss program. Cox, JS., Kreitzman, SN., Coxon, AY., et al.[2018]

Low and very low calorie diets can effectively initiate weight loss and improve obesity-related health issues, but they should only be used under professional supervision due to the risk of severe complications.

Sustained long-term weight loss relies on making permanent lifestyle changes in diet and physical activity, rather than solely relying on low-calorie diets.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low and very low calorie diets. Atkinson, RL.[2019]

The very-low-calorie ketogenic diet (VLCKD) is an effective lifestyle intervention for managing overweight and obesity, leading to significant weight loss and improvements in conditions like hypertension, type 2 diabetes, and dyslipidemia.

This review synthesizes evidence from four key studies, highlighting VLCKD's potential benefits and offering practical recommendations for its implementation in adults.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Very-low-calorie ketogenic diet for the management of obesity, overweight and related disorders. Castellana, M., Biacchi, E., Procino, F., et al.[2021]

Very low-calorie diets (VLCDs), providing 800 kcal/day or less, can lead to significant weight loss of 1.5 to 2.5 kg per week, with an average total loss of 20 kg over 12 to 16 weeks, which is more effective than standard low-calorie diets.

VLCDs are generally safe for moderately and severely obese patients when supervised by medical professionals, although long-term weight maintenance remains a challenge; incorporating behavioral therapy and physical activity can help improve outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Very low-calorie diets. National Task Force on the Prevention and Treatment of Obesity, National Institutes of Health. [2022]

Very low calorie diets can lead to significant weight loss, averaging 20 kg in just 12 weeks, making them effective for treating moderate to severe obesity.

When conducted under careful medical supervision for up to 3 months, these diets are considered safe, with no diet-related fatalities reported in over 10,000 cases, contrasting sharply with earlier liquid protein diets that had serious safety concerns.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Very low calorie diets: their efficacy, safety, and future. Wadden, TA., Stunkard, AJ., Brownell, KD.[2022]

In a study of 44 patients with obesity, a Very Low Calorie Diet (VLCD) resulted in an average weight loss of 7 kg and a weight loss rate of 1.2 kg per week, indicating its effectiveness for weight management.

While 33% of participants reported mild side effects, such as constipation and dizziness, the majority (84%) adhered to the VLCD, suggesting that with proper support, adherence can be maintained.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Effectiveness and safety of Very Low Calory Diets in obese patients]. Sáez Belló, M., Segarra Villalba, C., Gras Colomer, E., et al.[2018]

References

1. United States pubmed.ncbi.nlm.nih.gov

Long-term outcome of a self-help very-low-calorie-diet weight-loss program. [2018]

2. United States pubmed.ncbi.nlm.nih.gov

Low and very low calorie diets. [2019]

3. United States pubmed.ncbi.nlm.nih.gov

Long-term maintenance of weight loss after a very-low-calorie diet: a randomized blinded trial of the efficacy and tolerability of sibutramine. [2022]

4. United States pubmed.ncbi.nlm.nih.gov

Very-low-calorie diets and sustained weight loss. [2007]

5. Italy pubmed.ncbi.nlm.nih.gov

Very-low-calorie ketogenic diet for the management of obesity, overweight and related disorders. [2021]

6. England pubmed.ncbi.nlm.nih.gov

VLCKD: a real time safety study in obesity. [2022]

7. United States pubmed.ncbi.nlm.nih.gov

Very low-calorie diets. National Task Force on the Prevention and Treatment of Obesity, National Institutes of Health. [2022]

8. United States pubmed.ncbi.nlm.nih.gov

Very low calorie diets: their efficacy, safety, and future. [2022]

9. Spain pubmed.ncbi.nlm.nih.gov

[Effectiveness and safety of Very Low Calory Diets in obese patients]. [2018]

10. England pubmed.ncbi.nlm.nih.gov

Different dietary strategies for weight loss in obesity: role of energy and macronutrient content. [2008]

11. England pubmed.ncbi.nlm.nih.gov

Very low energy formula diet in the treatment of obesity. [2014]