Demystifying Diets- Intermittent fasting and Calorie control

Demystifying Diets- Intermittent fasting and Calorie control

There are many diets out there, but which ones are safest, most effective and sustainable. We delve into dieting and compare intermittent fasting and calorie control or restriction. Intermittent fasting is a diet regimen that cycles between brief periods of fasting, with either no food or significant calorie reduction, and periods of unrestricted eating. It is promoted to change body composition through loss of fat mass and weight, and to improve markers of health that are associated with disease such as blood pressure and cholesterol levels. We do it naturally everyday between dinner and breakfast but does having extended periods really help with weight control. Read on.

Prolonged very low-calorie diets can cause physiological changes that may cause the body to adapt to the calorie restriction and therefore prevent further weight loss. Intermittent fasting attempts to address this problem by cycling between a low-calorie level for a brief time followed by normal eating, which may prevent these adaptations. However, research does not consistently show that intermittent fasting is superior to continuous low-calorie diets for weight loss efficiency. The below post is targeted towards those struggling with their weight or maintain a healthy calorie balance.

Types of Fasting

Alternate-day fasting—Alternating between days of no food restriction with days that consist of one meal that provides about 25% of daily calorie needs. Example: Mon-Wed-Fri consists of fasting, while alternate days have no food restrictions.
Whole-day fasting—1-2 days per week of complete fasting or up to 25% of daily calorie needs, with no food restriction on the other days. Example: The 5:2 diet approach advocates no food restriction five days of the week, cycled with a 400-500 calorie diet the other two days of the week.
Time-restricted feeding—Following a meal plan each day with a designated time frame for fasting. Example: Meals are eaten from 8am-3pm, with fasting during the remaining hours of the day.

Does it work?

Physiologically, calorie restriction has been shown in animals to increase lifespan and improve tolerance to metabolic stress in the body. Although the evidence for caloric restriction in animal studies is strong, there is less convincing evidence in human studies. Proponents of the diet believe that the stress of intermittent fasting causes an immune response that repairs cells and produces positive metabolic changes (reduction in triglycerides, LDL cholesterol, blood pressure, weight, fat mass, blood glucose). An understandable concern of this diet is that followers will overeat on non-fasting days to compensate for calories lost during fasting. However, studies have not shown this to be true when compared with other weight loss methods.

Calorie controlled/ restricted diets Vs intermittent fasting

Dropout rates ranged from 0-65%. When comparing dropout rates between the fasting groups and continuous calorie restriction groups, no significant differences were found. Overall, the review did not find that intermittent fasting had a low dropout rate, and therefore was not necessarily easier to follow than other weight loss approaches.
There was no significant difference in weight loss amounts or body composition changes between fasting and calorie-controlled diets.
No overall increase in appetite in the intermittent fasting groups despite significant weight loss and decreases in leptin hormone levels (a hormone that suppresses appetite).
No significant differences in blood pressure, heart rate, fasting glucose, and fasting insulin. At 12 months, although there were no differences in total cholesterol
The dropout rate was higher in the alternate-day fasting group (38%) than in the daily calorie restriction group (29%). Interestingly, those in the fasting group ate less food than prescribed on non-fasting days though they ate more food than prescribed on fasting days.

Suggested Benefits (Majority of which currently in Animal studies)

Reduced body fat, mass and waist line- Lower insulin levels, higher growth hormone levels and increased amounts of adrenaline all increase the breakdown of body fat and facilitate its use for energy. For this reason, short-term fasting increases your metabolic rate by helping you burn even more calories. In other words, intermittent fasting works on both sides of the calorie equation. It boosts your metabolic rate (increases calories out) and reduces the amount of food you eat (reduces calories in).
Can Reduce Insulin Resistance, Lowering Your Risk of Type 2 Diabetes
Can Reduce Oxidative Stress and Inflammation in The Body
Improve heart health- shown to improve numerous different risk factors, including blood pressure, total and LDL cholesterol, blood triglycerides, inflammatory markers and blood sugar levels
Brain heath and Alzheimer’s- Intermittent fasting improves various metabolic features known to be important for brain health
Live longer- Studies in rats have shown that intermittent fasting extends lifespan in a similar way as continuous calorie restriction

Potential Pitfalls and Disclaimers

Whilst intermittent fasting has many proven benefits, it is unclear that intermittent fasting is superior to other weight loss methods regarding the amount of weight loss, biological changes, compliance rates, and decreased appetite. More high-quality studies including randomized controlled trials with a longer follow up are needed to show a direct effect and the possible benefits of intermittent fasting. Strong recommendations on intermittent fasting for weight loss cannot be made at this time in humans, but we cannot disregard it as an avenue of exploration when attempting weight loss.

This blog is written for adults with health issues, including obesity, that could benefit from intermittent fasting. People who should not fast includes people who are underweight or have eating disorders like anorexia, pregnant or breastfeeding women, and people under the age of 18. Possibly danger with regards to medications, especially those with diabetes whose medications may need adapting- if any medical conditions or in any doubt please consult your doctor.

Summary

To restore balance or to lose weight, we simply need to increase the amount of time we burn food energy. That’s intermittent fasting. In essence, fasting allows the body to use its stored energy. That is how our bodies are designed. That’s what dogs, cat, lions and bears do. That’s what humans do. It makes logical sense, yet medical opinion is divided. Again, with all diets, foods and healthy balance we must be conscious of what we are consuming, move often and become active and seek advice if unsure.

Information taken from Department of Nutrition, Harvard University, the BBC, British Medical Journal (Systematic reviews)