Eating Almonds Before a Meal to Control Blood Sugar

Interindividual Variability in the Effect of Premeal Almond Supplementation on Glycemic Control - a Double Crossover Study

The goal of this study is to learn whether eating a small serving of almonds before meals can improve blood sugar control in adults who have early signs of problems with blood sugar regulation. The main questions it aims to answer are:

1. Does eating almonds before a meal reduce the rise in blood sugar after eating?
2. Do some people consistently benefit more than others from eating almonds before meals?

Large rises in blood sugar after eating are an early warning sign of type 2 diabetes, and simple dietary strategies may help lower this risk. This study aims to understand whether eating a small serving of almonds before meals can help reduce postprandial blood sugar levels in adults who are at increased risk for developing type 2 diabetes. Participants will take part in two phases of the study: one conducted in a research clinic to carefully measure short-term blood sugar responses, and another conducted while participants follow a provided diet at home over a longer period. Sometimes participants will eat almonds before meals, and sometimes they will not. The study hypothesis is that eating almonds before meals will lower blood sugar rises after eating, and that some people will benefit more than others in a consistent way that can be observed both in the clinic and during everyday living.

Inclusion Criteria:

• Adults aged 25-50 years
• Females over 40 years must have had a cycle in the last 6 months
• Body mass index (BMI) at least 18.5 and at most 55.0 kg/m2
• Impaired blood glucose by at least one of the following criteria:
• Fasting blood glucose at least 100 mg/dL (5.6 mmol/L) and less than 125 mg/dL (6.9 mmol/L)
• HbA1c at least 5.7% and less than 6.5%
• Willing and able to comply with study foods
• Willing and able to ingest acetaminophen as part of study procedures
• Able to read, speak, and understand English

Exclusion Criteria:

• Weight change ≥5% in past 6 months, actively trying to lose weight, or unwilling to remain weight stable throughout the study based on self-report
• Recent history within past 12 months of medical provider-diagnosed cardiovascular, renal, or liver disease that required treatment
• Current or past diagnosis of cancer (except skin cancer) in the last 5 years
• Current or past diagnosis of type 1 or type 2 diabetes
• Recent history within past 12 months of medical provider-diagnosed gastrointestinal or neurological disorders if not managed/stable for at least 3 months (with or without treatment)
• Recent history within past 12 months of medical provider-diagnosed psychiatric disorders including eating disorders or severe depression if not managed/stable for at least 3 months (with or without treatment)
• Food allergies or other reasons preventing consumption of study foods
• Any glucose-lowering medication except biguanides (e.g., Metformin) if stable for at least 3 months or incretins (i.e., GLP-1RA-based) if stable for at least 3 months
• Current smoking or vaping or history of smoking or vaping in the past 6 months
• Binge and/or heavy drinking (i.e., >3 drinks on any given occasion and/or >7 drinks/week)
• Currently pregnant or planning to become pregnant or breastfeed in the next 3 months by self-report