Ready to lose weight? Just order the Isagenix 30-Day System. Open the box and follow the simple instructions. And… bam! Results! Well, not exactly. Whilst this may work for many, there are some individuals who may need to customise their systems, particularly their Shake Days.

Within the Isagenix System, a Shake Day consists of two IsaLean or IsaLean Pro Shakes, two small 100-150 calorie snacks and a 400-600 calorie meal, which adds up to around 1,200 to 1,500 calories per day (see our recommended Shake Day schedule) For most sedentary, middle-age to older adults who only burn around 1,800 to 2,000 calories each day, the 1,200- to 1,500 calorie range is just right for weight loss.

But there are others who have daily energy requirements that are much higher. Activity level, gender and body size can each greatly influence a person’s calorie requirements, creating the need for more food.

For example, men typically have larger frames and more muscle mass to support than women. A man of average weight and activity level, who stands at 183cm tall could require upwards of 2,700 calories just to maintain weight, whilst a 200cm tall man might easily require more than 3,500 calories. And regardless of body size or gender, a person who is extremely active or works a physically demanding job will also have higher energy requirements.

A person requiring 3,000 calories per day put on a regimen providing just 1,500 calories likely wouldn’t stay on it long as it would lead to hunger and fatigue. The best plan is the one that cuts calories by the minimum amount needed to produce fat loss, or around 500 calories below what is needed to maintain weight.

If you find comfort in the one-size-fits-all instructions offered by the Isagenix System, the idea of modifying your Shake Day may be a little intimidating at first. But don’t worry! We’ve put together a step-by-step guide that will not only help you to determine whether you need to modify your Shake Day but will also show you how to customise your Shake Day to ensure weight-loss success.

Steps to Customised Shake Days

STEP 1: Determine whether you’ll need extra calories

As a first step in figuring out whether you may need to modify your Shake Day, ask yourself:

  1. Am I a male with a larger frame?
  2. Am I an athlete or do I work a physically demanding job?

If the answer is yes to either of these questions, you should customise your Shake Day. You’ve established that you have higher energy needs than the average sedentary adult and now need to decide how to modify your Shake Day to ensure optimal weight-loss success. To do this, you’ll first need to set a target calorie goal for your Shake Day, which can be done by completing the next step.

STEP 2: Figure out your target calorie goal for Shake Days

There are two ways to figure out how many calories you should be eating to lose weight. The first is to go to an online website that offers a calorie calculator, such as The calculator will generate a specific amount of calories that you should be eating to lose weight based on your gender, age, height, weight and activity level. Because this number is based on an equation, it should be kept in mind that it may not be completely accurate and will likely need to be adjusted based on your body’s response.

A more accurate way of determining your daily target calorie goal for weight loss is to figure out about how many calories you are currently eating to maintain weight and then reduce this number by 500. You can download any calorie tracking app, such as MyFitnessPal or MyNetDiary, and enter all of the food you eat each day into the tracking database. Do this for five days and then figure out the average calorie intake per day. Cut this number by 500 and you’ll have your target calorie goal for Shake Days.

Example: Your average calorie intake after five days is 2,600 calories: 2600 – 500 = 2100 calories per Shake Day.

STEP 3: Add calories to the shakes, snacks and third meal to meet your target calorie goal

Now that you’ve set your target calorie goal for your Shake Day, it’s time to implement a strategy to increase your intake so that you can hit this number. The best way to do this is to add calories to the IsaLean or IsaLean Pro shakes, to increase the calories in your snacks and/or to add calories to your standard 400- to 600-calorie meal.

  • Easy ways to add about 100 calories to your shake:
    • Add one serving of fruit
    • Add 4 tbsp. of oats
    • Add 1 tbsp. of nut butter
    • Mix shake with one cup (250mL) low-fat milk or almond milk
  • 200- to 300-calorie snack ideas:
    • 1 IsaLean Bar
    • ½ cup hummus and fresh vegetables
    • Pair 1 cup of low-fat Greek yogurt with:
        • A serving of fruit
        • 1 Fibre Snack™ bar
        • ½ cup of granola
        • 3 tbsp. trail (nut) mix
        • 1 Slim Cake™ + 10 almonds
  • Add calories to your 400- to 600-calorie meal
    • You should already have 30 to 40 grams of protein in your third meal (learn What to Have For a Third Meal on Isagenix Shake Days) but you can easily bulk this meal up by adding an extra serving of carbohydrate-based foods or an extra serve of healthy fats to your meal.

This is what a Shake Day might look like for someone with a 2100-calorie target goal:

  • Breakfast: IsaLean Pro Shake + banana = 400 calories
  • Mid-morning Snack: 1 Fibre Snack bar dipped in 1 cup of fat-free plain Greek yogurt = 280 calories
  • Lunch: IsaLean Pro Shake + 4 tbsp. oats = 400 calories
  • Mid-afternoon Snack: 1 IsaLean Nutty Caramel Cashew Bar = 240 calories
  • Dinner: Large third meal (1 additional serving of carbs, 1 additional serving of healthy fats) = 800 calories

One of the great things about the Isagenix System is that it’s easily customised to the individual to make losing weight easier. Don’t be afraid to personalise your Shake Days. Often a unique approach, tailored to the individual, is the best way to ensure weight-loss success.

Looking for tips for your Cleanse Day schedule? Check out Tips for Your Best Cleanse Day Ever.

*Weight-loss results depicted here should not be construed as typical or average. In a study performed in 2012 by University at Chicago researchers, subjects lost an average of 4.1 kg with an average of 0.9 kg of the loss from visceral fat after 30 days on an Isagenix System. The subjects also had a greater level of adherence and had more consistent weight loss from week to week compared to subjects on a traditional diet. Always consult your GP before making any dietary changes or starting any nutrition, weight-loss or exercise program.

If you are pregnant, breastfeemding, diabetic, on medication, have a medical condition or are beginning a weight loss program, consult your GP before using Isagenix products or making any other dietary changes. Discontinue use if adverse event occur.

Information provided on this Web site and on all publications, packaging, and labels is for general purposes only and designed to help you make informed decisions about your health. It is not intended to substitute advice from your physician or health-care professional.