No. A slimfast bar is not a lunch. Your body will pick up on it (and the added sugar on it) and give you a sudden spike of glucose. Because it's not a slow release of energy your blood sugar levels will quickly dip, which will make your body a) crave more food, b) go into starvation mode.
Starvation mode: Which means anything else you do eat will have a greater portion stored as fat than if you just ate a regular meal.
January 2017: I picked up my activity levels. I was 65kg. I started ice skating and hired a personal trainer. I would go to the gym 3 days a week.
Skate for 2 hours in the morning, have personal training for 1 hour, do cardio for 1 hour, extra weights for half hour, stretch for 1 hour and go home.
Diet:
- Breakfast :
Plain porridge with semi-skimmed milk and a handful of fruits (sometimes I forget the fruit) + 1 cup of tea.
Maybe once a week I'll have a fried egg with a slice of brown bread with butter + 1 cup of tea.
- Mid-morning snack (only on exercise days): Protein shake with semi-skimmed milk (maybe 150mls)
- Lunch:
Half and 8" Plate is a salad. I prefer iceberg lettuce with beetroot, lemon and a drizzle of olive oil and a fresh tomato.
Quarter plate is a piece of lean meat. (Fish, chicken, turkey, I sometimes have red meat but rarely) I cook it with that spray olive oil they sell, so I make sure I don't add too much oil.
Quarter plate (basmati rice, or beans or non-starchy carbs... like sweet potato)
-Afternoon snack: Nuts, a piece of fruit, natural yoghurt. Depends how hungry I feel I'll either have one, two or all three.
- Dinner: Same as lunch.
Add a couple or more teas throughout the day and that's what I've eaten for a year. Plus all that exercise.
I've lost 5kg.
That being said, I have lost inches all round, which means I've likely lost a lot of fat and gained a fair amount of muscle.
What I'm saying is don't focus on the weight because you'll be grossly disappointed. And if you get halfway to your ideal weight in seven weeks I'll be impressed (but also worried for you) but there will be absolutely no way you will keep that weight down. It's not a matter or losing weight in a handful of weeks and there, you'll keep it that way for the rest of the 10 months of school, it has to be a lifestyle change, which means a much healthier meal option than what you have written down. And finding a schedule that will work not only while you're on holiday, but that will work around your studies because the exercise and diet has to be kept up for it to have a lasting effect.
On another note, a body on starvation mode loses fat but also loses muscle. Your heart is made of muscle, so loosing weight rapidly is only going to make you weaker, not stronger.
It can be done, but for you to be happy with it and see lasting results you have to be patient and make it a long goal that will hopefully stick with you for many years to come.