Type 2 Diabetes: Dietary Management

Learning Outcomes

  • Understand the importance of glycaemic control to reduce the risk of complications in type 2 diabetes:

    • Dietary approaches involve glycaemic control

    • Key components include:

      • Glycaemic index

      • Carbohydrate content

      • Meal timings

  • Understand the role of macronutrients (particularly carbohydrates and fats) on glycaemic control

  • Nutritional strategies for preventing and managing complications of cardiovascular disease (CVD)

  • Role of weight management in diabetes prevention

Glucose Targets

  • Target HbA1c level: 48 mmol/mol

    • Lifestyle and diet adjustments are key for maintaining this target.

    • For individuals not achieving control with a single drug, if HbA1c rises to >= 58 mmol/mol:

    → Reinforce advice about diet, lifestyle, and adherence to drug treatment    

    → Support aiming for an HbA1c level of 53 mmol/mol

    → Intensify drug treatment as necessary.

Complications of Type 2 Diabetes

Acute Complications

  • Hypoglycaemia: Blood sugar levels drop too low, generally below 4 mmol/L

    • Treatment options include: 15-20g glucose

    • Fast-acting glucose shots (e.g., 60ml of glucose drink)

    • Five glucose or dextrose tablets

    • Four jelly babies

    • Small glass of sugary (non-diet) drink (150-200ml)

    • Small carton of pure fruit juice (200ml)

    • Glucose gel tubes like GlucoGel® or RapiloseⓇ Gel

    • Products like Lift Shots®

→ Recheck BG level after 15 mins, may need to take some slow releasing carbs to maintain BG level.

→ From dietetic perspective, frequent hypos increase calorie intake - first stage is ~ 60kcals, also not good for dental health.

  • Hyperglycaemia and Hyperosmolar Hyperglycaemia State (HHS)

Dietary Management Recommendations

  • Guidelines from the NICE (National Institute for Health and Care Excellence) published on Dec 2, 2015, updated June 29, 2022.

  • Recommended Dietary Approaches:

    • Healthy, cardioprotective diet

    • Low glycaemic index/load

    • Calorie-controlled diet

    • Low carbohydrate diet

    • Total diet replacement strategy

  • Emphasis on no one-size-fits-all approach

    • Engage with individual dietary needs and preferences.

Eatwell Guide Principles

  • Utilize the Eatwell Guide to balance healthier and sustainable food consumption, highlighting:

    • Portion sizes and groups of foods for a balanced diet.

    • Daily recommendations include:

    • 5 portions of a variety of fruit and vegetables.

    • Lower fat, salt, and sugars.

    • Focus on wholegrain options for starchy carbohydrates.

    • Limit fruit juice to a maximum of 150ml daily.

    • Portion control in consuming meats, dairy, and processed foods.

  • Important to use relevant Eatwell guide e.g. South Asian Eatwell guide.

Dietary Principles for Type 2 Diabetes

  • Follow general healthy eating advice, which includes:

    • High-fibre, low-glycaemic-index carbohydrate sources (fruits, vegetables, wholegrains, pulses)

    • Low-fat dairy products

    • Regular intake of oily fish

    • Control the intake of saturated and trans fatty acids

  • Discourage the intake of products specifically marketed for individuals with diabetes.

Carbohydrate and Alcohol Intake Recommendations

  • Individual recommendations necessary for carbohydrate and alcohol intake.

  • Specific aim to reduce hypoglycaemia risk for individuals using insulin or an insulin secretagogue.

Glycaemic Index and Glycaemic Load

  • Glycaemic Index (GI): Ranks carbohydrate-containing food according to how much it raises blood glucose (BG) levels compared to a reference food (pure glucose or white bread).

  • Glycaemic Load (GL): Calculated as GI multiplied by the available carbohydrate (g) in the serving divided by 100.

  • Important to note that other factors can influence overall glycaemic affect: meal composition - fats and proteins can slow down glucose rise, cooking type/methods, type of starch.

Cardiovascular Disease Management in Diabetes

  • Target management strategies include from Landmark UKPDS study:

    • Maintaining blood pressure at or below 140/80 mmHg

    • If kidney issues present, aim for 130/80 mmHg

    • Total cholesterol should be < 4 mmol/L

  • Dietary adjustments: Reduce salt intake (<6g/day), increase intake of oily fish (two portions weekly), improve consumption of wholegrains, fruits, vegetables, and legumes while decreasing red and processed meats, refined carbohydrates, and sugar-sweetened beverages.

    • Replace saturated fats with unsaturated fats and limit trans fats.

    • Alcohol intake should be limited to < 14 units/week.

    • Aim for modest weight loss (at least 5%) in overweight individuals and encourage at least 150 minutes of moderate-intensity physical activity weekly.

Managing weight

Benefit

Mortality

>20% fall

>30% fall in diabetes related deaths

Blood Pressure

Fall of 10mmHg systolic

Fall of 20mmHg diastolic

Diabetes

Fall of 50% in fasting glucose

Lipids

Fall 10% total cholesterol

Fall of 15% low density lipoprotein

Fall of 30% triglycerides

Rise of 8% high density lipoprotein

  • For overweight or obese individuals with type 2 diabetes:

    • For T2D remission, aim for weight loss of approximately 15kg as soon as possible after diagnosis.

    • To improve glycaemic control and CVD risk, 5% weight loss aim achieved by reducing calorie intake and increasing energy expenditure.

    • Individualized strategies may include dietary modifications, physical activity, surgical options, and medications.

Low Carbohydrate Diet

  • Defined categories of carbohydrate intake in daily diets based on a 2000 kcal/day diet:

    • Very Low Carbohydrate: 20-50g/day (≤10% of total daily energy)

    • Ketogenic: Same as very low carbohydrate

    • Low Carbohydrate: <130g/day (<26%)

    • Moderate Carbohydrate: 130-230g/day (26-45%)

    • High Carbohydrate: >230g/day (>45%)

  • Brain needs glucose to function and needs 100-120g per day - how low carb and very low carb diet intake calculated.

Very Low Carbohydrate and Ketogenic Diets

  • A very low carbohydrate diet contains 20 to 50 grams of carbohydrates per day (less than 10% of a 2000 kcal/day diet), while a ketogenic diet is formulated to induce ketosis through a very low carbohydrate, high fat diet.

Total Diet Replacement (DIRECT Trial)

  • Treatment Methodology:

    • Weight Loss Stage: Total Diet Replacement involving shakes and soups.

    • Duration: 12 Weeks with weekly or biweekly appointments for targets.

    • Intake during weight loss is 810+ calories/day.

    • Reintroduction Stage: Gradual introduction of portion-controlled meals over another 12 weeks.

    • Maintenance Stage: Focus on maintaining lifestyle changes over 6 months, including up to 18 monthly appointments for ongoing support and potential weight loss medication.

  • Almost half (46%) of patients were in remission after 1 year.

Outcomes from ReTUNE Study (2022)

The mechanistic changes behind type 2 diabetes remission among patients considered non-obese by BMI standards were the same as those observed in patients who were considered obese.

  • Results Post 12 Months:

    • Average BMI reduced to 22.4 kg/m² from 24.8 kg/m².

    • 70% of participants achieved remission from type 2 diabetes with half achieving it after the first weight loss cycle.

    • Intervention was low calorie diet.

    • Participants needed to lose an average of 8% body weight for remission.

    • In 14 out of 20 participants who went into remission, their average HbA1c fell from 53mmon/mol at start to 45mmol/mol. Their bp dropped despite taking less medication to treat this.

    • Participants liver and pancreas fat levels were higher than expected at start of trial but decreased to normal levels after weight loss.

NHS Type 2 Diabetes Path to Remission Programme

  • A joint initiative providing total diet replacement treatments for eligible overweight or obese individuals with type 2 diabetes.

Physical Activity Recommendations

  • Definition of Physical Activity: Movement resulting in energy expenditure; includes planned, repetitive exercise for fitness, divided into:

    • Aerobic: Endurance-focused.

    • Anaerobic: Strength and power.

  • Resistance Training: Specific muscle group exercises against resistance.

  • Benefits for Adults and Older Adults:

    • Sleep improvement

    • Weight management

    • Stress relief

    • Reduction of type 2 diabetes risk by 40%

    • Cardiovascular disease risk reduction by 35%

    • Falls and depression risk reduction by 30%

    • Joint and back pain reduction by 25%

    • Cancer risk (colon and breast) reduction by 20%.

  • Aim for at least 150 minutes of moderate-intensity activity per week, with recommendations for strength and balance exercises for older adults.

Structured Education in Diabetes Management

  • The DESMOND program provides structured education to adults with type 2 diabetes at diagnosis, with annual reinforcement and review.

  • Emphasizes the significance of structured education as part of overall diabetes care.

Evidence-Based Nutrition Guidelines

  • Nutrition guidelines for diabetes management suggest strategies for prevention and management, established in March 2018 for consistent application across treatment plans.

Conclusion

  • The importance of glycaemic control in preventing complications, dietary approaches, macronutrient roles, and weight management in diabetes management have been extensively covered and should inform therapeutic strategies.